Efficient Communication for Devices of a Home Network

ABSTRACT

Systems and methods are provided for efficient communication through a fabric network of devices in a home environment or similar environment. For example, an electronic device may efficiently control communication to balance power and reliability concerns, may efficiently communicate messages to certain preferred networks by analyzing Internet Protocol version 6 (IPv6) packet headers that use an Extended Unique Local Address (EULA), may efficiently communicate software updates and status reports throughout a fabric network, and/or may easily and efficiently join a fabric network.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of, and claims priorityto, U.S. patent application Ser. No. 13/926,335, entitled “EfficientCommunication for Devices of a Home Network”, filed Jun. 25, 2013, theentirety of which is incorporated by reference herein for all purposes.

BACKGROUND

This disclosure relates to efficient communication to enable variousdevices, including low-power or sleepy devices, to communicate in a homenetwork or similar environment.

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the present techniques,which are described and/or claimed below. This discussion is believed tobe helpful in providing the reader with background information tofacilitate a better understanding of the various aspects of the presentdisclosure. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

Network-connected devices appear throughout homes. Some of these devicesare often capable of communicating with each other through a singlenetwork type (e.g., WiFi connection) using a transfer protocol. It maybe desired to use less power intensive connection protocols for somedevices that are battery powered or receive a reduced charge. However,in some scenarios, devices connected to a lower power protocol may notbe able to communicate with devices connected to a higher power protocol(e.g., WiFi).

Moreover, numerous electronic devices are now capable of connecting towireless networks. For example, smart meter technology employs awireless network to communicate electrical energy consumption dataassociated with residential properties back to a utility for monitoring,billing, and the like. As such, a number of wireless networkingstandards are currently available to enable electronic devices tocommunicate with each other. Some smart meter implementations, forinstance, employ Internet Protocol version 6 (IPv6) over Low powerWireless Personal Area Networks (6LoWPAN) to enable electronic devicesto communicate with a smart meter. However, the currently availablewireless networking standards such as 6LoWPAN may not be generally wellequipped to support electronic devices dispersed throughout a residenceor home for one or more practical scenarios. That is, the currentlyavailable wireless networking standards may not efficiently connect allelectronic devices of a network in a secure yet simple,consumer-friendly manner in view of one or more known practicalconstraints. Moreover, for one or more practical scenarios, thecurrently available wireless networking standards may not provide anefficient way to add new electronic devices to an existing wirelessnetwork in an ad hoc manner.

Additionally, when providing a wireless network standard for electronicdevices for use in and around a home, it would be beneficial to use awireless network standard that provides an open protocol for differentdevices to learn how to gain access to the network. Also, given thenumber of electronic devices that may be associated with a home, itwould be beneficial that the wireless network standard be capable ofsupporting Internet Protocol version 6 (IPv6) communication such thateach device may have a unique IP address and may be capable of beingaccessed via the Internet, via a local network in a home environment,and the like. Further, it would be beneficial for the wireless networkstandard to allow the electronic devices to communicate within thewireless network using a minimum amount of power. With these features inmind, it is believed that one or more shortcomings is presented by eachknown currently available wireless networking standard in the context ofproviding a low power, IPv6-based, wireless mesh network standard thathas an open protocol and can be used for electronic devices in andaround a home. For example, wireless network standards such asBluetooth®, Dust Networks®, Z-wave®, WiFi, and ZigBee® fail to provideone or more of the desired features discussed above.

Bluetooth®, for instance, generally provides a wireless network standardfor communicating over short distances via short-wavelength radiotransmissions. As such, Bluetooth's® wireless network standard may notsupport a communication network of a number of electronic devicesdisposed throughout a home. Moreover, Bluetooth's® wireless networkstandard may not support wireless mesh communication or IPv6 addresses.

As mentioned above, the wireless network standard provide by DustNetworks® may also bring about one or more shortcomings with respect toone or more features that would enable electronic devices disposed in ahome to efficiently communicate with each other. In particular, DustNetworks'® wireless network standard may not provide an open protocolthat may be used by others to interface with the devices operating onDust Networks' network. Instead, Dust Networks® may be designed tofacilitate communication between devices located in industrialenvironments such as assembly lines, chemical plants, and the like. Assuch, Dust Networks'® wireless network standard may be directed toproviding a reliable communication network that has pre-defined timewindows in which each device may communicate to other devices and listenfor instructions from other devices. In this manner, Dust Networks'®wireless network standard may require sophisticated and relativelyexpensive radio transmitters that may not be economical to implementwith consumer electronic devices for use in the home.

Like Dust Networks'® wireless network standard, the wireless networkstandard associated with Z-wave® may not be an open protocol. Instead,Z-wave's® wireless network standard may be available only to authorizedclients that embed a specific transceiver chip into their device.Moreover, Z-wave's® wireless network standard may not support IPv6-basedcommunication. That is, Z-wave's® wireless network standard may requirea bridge device to translate data generated on a Z-wave® device intoIP-based data that may be transmitted via the Internet.

Referring now to ZigBee's® wireless network standards, ZigBee® has twostandards commonly known as ZigBee® Pro and ZigBee® IP. Moreover,ZigBee® Pro may have one or more shortcomings in the context of supportfor wireless mesh networking Instead, ZigBee® Pro may depend at least inpart on a central device that facilitates communication between eachdevice in the ZigBee® Pro network. In addition to the increased powerrequirements for that central device, devices that remain on to processor reject certain wireless traffic can generate additional heat withintheir housings that may alter some sensor readings, such as temperaturereadings, acquired by the device. Since such sensor readings may beuseful in determining how each device within the home may operate, itmay be beneficial to avoid unnecessary generation of heat within thedevice that may alter sensor readings. Additionally, ZigBee® Pro may notsupport IPv6 communication.

Referring now to ZigBee® IP, ZigBee® IP may bring about one or moreshortcomings in the context of direct device-to-device communication.ZigBee® IP is directed toward the facilitation of communication by relayof device data to a central router or device. As such, the centralrouter or device may require constant powering and therefore may notrepresent a low power means for communications among devices. Moreover,ZigBee® IP may have a practical limit in the number of nodes (i.e., ˜20nodes per network) that may be employed in a single network. Further,ZigBee® IP uses a “Ripple” routing protocol (RPL) that may exhibit highbandwidth, processing, and memory requirements, which may implicateadditional power for each ZigBee® IP connected device.

Like the ZigBee® wireless network standards discussed above, WiFi'swireless network may exhibit one or more shortcomings in terms ofenabling communications among devices having low-power requirements. Forexample, WiFi's wireless network standard may also require eachnetworked device to always be powered up, and furthermore may requirethe presence of a central node or hub. As known in the art, WiFi is arelatively common wireless network standard that may be ideal forrelatively high bandwidth data transmissions (e.g., streaming video,syncing devices). As such, WiFi devices are typically coupled to acontinuous power supply or rechargeable batteries to support theconstant stream of data transmissions between devices. Further, WiFi'swireless network may not support wireless mesh networking Even so, WiFisometimes may offer better connectivity than some lower-poweredprotocols.

SUMMARY

A summary of certain embodiments disclosed herein is set forth below. Itshould be understood that these aspects are presented merely to providethe reader with a brief summary of these certain embodiments and thatthese aspects are not intended to limit the scope of this disclosure.Indeed, this disclosure may encompass a variety of aspects that may notbe set forth below.

Systems and methods are provided for efficient communication through afabric network of devices in a home environment or similar environment.For example, an electronic device may efficiently control communicationto balance power and reliability concerns, may efficiently communicatemessages to certain preferred networks by analyzing Internet Protocolversion 6 (IPv6) packet headers that use an Extended Unique LocalAddress (EULA), may efficiently communicate software updates and statusreports throughout a fabric network, and/or may easily and efficientlyjoin a fabric network.

For instance, an electronic device may include memory or storage storinginstructions to operate a network stack, a processor to execute theinstructions, and a network interface to join a network-connected fabricof devices and communicate a message to a target device of the fabric ofdevices using the network stack. The network stack may include anapplication layer to provide an application payload with data to betransmitted in the message, a platform layer to encapsulate theapplication payload in a general message format of the message, atransport layer to selectably transport the message using either UserDatagram Protocol (UDP) or Transmission Control Protocol (TCP), and anetwork layer to communicate the message using Internet Protocol Version6 (IPv6) via one or more networks. These networks may include, forexample, an 802.11 wireless network, an 802.15.4 wireless network, apowerline network, a cellular network, and/or an Ethernet network.Moreover, the application layer, the platform layer, the transportlayer, and/or the network layer may determine a property of the mannerof communication of the message to the target node based at least inpart on a type of the messag, the network over which the message is tobe sent, a distance over which the message may travel through thefabric, power consumption behavior of the electronic device, powerconsumption behavior of the target device, and/or power consumptionbehavior of an intervening device of the fabric of devices that is tocommunicate the message between the electronic device and the targetdevice. Further, varying the property of the manner of communication maycause the electronic device, the target device, and/or the interveningdevice to consume different amounts of power and cause the message tomore reliably or less reliably reach the target node.

In another example, a tangible, non-transitory computer-readable mediummay include to be executed by a first electronic device communicablycoupled to other electronic devices of a fabric of devices in a homeenvironment. The instructions may include those to receive an InternetProtocol version 6 (IPv6) message at the first electronic device from asecond electronic device over a first network of the fabric of devices.The message may be bound for a target electronic device. Theinstructions may further include instructions to identify an ExtendedUnique Local Address encoded in an IPv6 header of the message. Here, theExtended Unique Local Address may indicate that a second network ispreferred to reach the target electronic device. The instructions alsomay include instructions to communicate the message through the fabricof devices toward the target electronic device using second networkbased at least in part on the Extended Unique Local Address.

A method for transferring a software update over a fabric network mayinclude sending an image query message from a first device in the fabricnetwork to a second device in the fabric network or a local or remoteserver. The image query message may include information regardingsoftware stored on the first device and transfer capabilities of thefirst device. An image query response may be received by the firstdevice from the second device or the local or remote server. The imagequery response may indicate whether the software update is available andincludes download information having a uniform resource identifier (URI)to enable the first device to download the software update. The imagequery message may include sender information regarding software storedon a sender device and transfer capabilities of the sender device and anupdate priority. Using the URI, the software update may be downloaded atthe first device from the sender device. The software may be downloadedat a time based at least in part on the update priority and networktraffic in the fabric network, and may be downloaded in a manner basedat least in part on common transfer capabilities indicated in the imagequery and the image query response.

In a further example, a tangible, non-transitory computer-readablemedium may store a status reporting format. The status reporting formatmay include a profile field to indicate a status update type of aplurality of status update types, a status code to indicate a statusbeing reported—the status code may be interpreted in a manner based atleast in part on the status update type—and a next status field toindicate whether an additional status is included in a status reportformed using the status reporting format.

Another example of an electronic device includes memory to storeinstructions to enable the first electronic device to pair with a fabricnetwork comprising a second electronic device, a processor to executethe instructions, and a network interface to access 802.11 and 802.15.4logical networks. The instructions may include instructions to establishcommunication with the second electronic device via a first 802.15.4logical network. The second electronic device may be paired with thefabric network and may communicate with a service via another logicalnetwork in the fabric network. The instructions may also includeinstructions to receive network configuration information from theservice via the second electronic device to enable the first electronicdevice to join a first 802.11 logical network and to establishcommunication over the first 802.11 logical network, connect to theservice via the first 802.11 logical network, and register to pair withthe fabric network via communication with the service.

Various refinements of the features noted above may be used in relationto various aspects of the present disclosure. Further features may alsobe incorporated in these various aspects as well. These refinements andadditional features may be used individually or in any combination. Forinstance, various features discussed below in relation to one or more ofthe illustrated embodiments may be incorporated into any of theabove-described aspects of the present disclosure alone or in anycombination. The brief summary presented above is intended only tofamiliarize the reader with certain aspects and contexts of embodimentsof the present disclosure without limitation to the claimed subjectmatter.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of this disclosure may be better understood upon readingthe following detailed description and upon reference to the drawings inwhich:

FIG. 1 illustrates a block diagram of a general device that maycommunicate with other devices disposed in a home environment using anefficient network layer protocol, in accordance with an embodiment;

FIG. 2 illustrates a block diagram of a home environment in which thegeneral device of FIG. 1 may communicate with other devices via theefficient network layer protocol, in accordance with an embodiment;

FIG. 3 illustrates an example wireless mesh network associated with thedevices depicted in the home environment of FIG. 2, in accordance withan embodiment;

FIG. 4 illustrates a block diagram of an Open Systems Interconnection(OSI) model that characterizes a communication system for the homeenvironment of FIG. 2, in accordance with an embodiment;

FIG. 5 illustrates a detailed view an efficient network layer in the OSImodel of FIG. 4, in accordance with an embodiment;

FIG. 6 illustrates a flowchart of a method for implementing a RoutingInformation Protocol—Next Generation (RIPng) network as a routingmechanism in the efficient network layer of FIG. 5, in accordance withan embodiment;

FIG. 7A-7D illustrates an example of how the RIPng network of the methodof FIG. 6 can be implemented, in accordance with an embodiment;

FIG. 8 illustrates a block diagram of a manufacturing process thatincludes embedding a security certificate into the general device ofFIG. 1, in accordance with an embodiment;

FIG. 9 illustrates an example handshake protocol between devices in thehome environment of FIG. 2 using a Datagram Transport Layer Security(DTLS) protocol in the efficient network layer of FIG. 5, in accordancewith an embodiment;

FIG. 10 illustrates the fabric network having a single logical networktopology, in accordance with an embodiment;

FIG. 11 illustrates the fabric network having a star network topology,in accordance with an embodiment;

FIG. 12 illustrates the fabric network having a overlapping networkstopology, in accordance with an embodiment;

FIG. 13 illustrates a service communicating with one or more fabricnetworks, in accordance with an embodiment;

FIG. 14 illustrates two devices in a fabric network in communicativeconnection, in accordance with an embodiment;

FIG. 15 illustrates a unique local address format (ULA) that may be usedto address devices in a fabric network, in accordance with anembodiment;

FIG. 16 illustrates a process for proxying periphery devices on a hubnetwork, in accordance with an embodiment;

FIG. 17 illustrates a tag-length-value (TLV) packet that may be used totransmit data over the fabric network, in accordance with an embodiment;

FIG. 18 illustrates a general message protocol (GMP) that may be used totransmit data over the fabric network that may include the TLV packet ofFIG. 17, in accordance with an embodiment;

FIG. 19 illustrates a message header field of the GMP of FIG. 18, inaccordance with an embodiment;

FIG. 20 illustrates a key identifier field of the GMP of FIG. 18, inaccordance with an embodiment;

FIG. 21 illustrates an application payload field of the GMP of FIG. 18,in accordance with an embodiment;

FIG. 22 illustrates a status reporting schema that may be used to updatestatus information in the fabric network, in accordance with anembodiment;

FIG. 23 illustrates a profile field of the status reporting schema ofFIG. 22, in accordance with an embodiment;

FIG. 24 illustrates a protocol sequence that may be used to perform asoftware update between a client and a server, in accordance with anembodiment;

FIG. 25 illustrates an image query frame that may be used in theprotocol sequence of FIG. 24, in accordance with an embodiment;

FIG. 26 illustrates a frame control field of the image query frame ofFIG. 25, in accordance with an embodiment;

FIG. 27 illustrates a product specification field of the image queryframe of FIG. 25, in accordance with an embodiment;

FIG. 28 illustrates a version specification field of the image queryframe of FIG. 25, in accordance with an embodiment;

FIG. 29 illustrates a locale specification field of the image queryframe of FIG. 25, in accordance with an embodiment;

FIG. 30 illustrates an integrity types supported field of the imagequery frame of FIG. 25, in accordance with an embodiment;

FIG. 31 illustrates an update schemes supported field of the image queryframe of FIG. 25, in accordance with an embodiment;

FIG. 32 illustrates an image query response frame that may be used inthe protocol sequence of FIG. 24, in accordance with an embodiment;

FIG. 33 illustrates a uniform resource identifier (URI) field of theimage query response frame of FIG. 32, in accordance with an embodiment;

FIG. 34 illustrates a integrity specification field of the image queryresponse frame of FIG. 32, in accordance with an embodiment;

FIG. 35 illustrates an update scheme field of the image query responseframe of FIG. 32, in accordance with an embodiment;

FIG. 36 illustrates a sequence used to employ a data management protocolto manage data between devices in the fabric network, in accordance withan embodiment;

FIG. 37 illustrates a snapshot request frame that may be used in thesequence of FIG. 36, in accordance with an embodiment;

FIG. 38 illustrates an example profile schema that may be accessed usingthe snapshot request frame of FIG. 37, in accordance with an embodiment;

FIG. 39 is a binary format of a path that may indicate a path in aprofile schema, in accordance with an embodiment;

FIG. 40 illustrates a watch request frame that may be used in thesequence of FIG. 36, in accordance with an embodiment;

FIG. 41 illustrates a periodic update request frame that may be used inthe sequence of FIG. 36, in accordance with an embodiment;

FIG. 42 illustrates a refresh request frame that may be used in thesequence of FIG. 36, in accordance with an embodiment;

FIG. 43 illustrates a cancel view request that may be used in thesequence of FIG. 36, in accordance with an embodiment;

FIG. 44 illustrates a view response frame that may be used in thesequence of FIG. 36, in accordance with an embodiment;

FIG. 45 illustrates an explicit update request frame that may be used inthe sequence of FIG. 36, in accordance with an embodiment;

FIG. 46 illustrates a view update request frame that may be used in thesequence of FIG. 36, in accordance with an embodiment;

FIG. 47 illustrates an update item frame that may be updated using thesequence of FIG. 36, in accordance with an embodiment;

FIG. 48 illustrates an update response frame that may be sent as anupdate response message in the sequence FIG. 36, in accordance with anembodiment;

FIG. 49 illustrates a communicative connection between a sender and areceiver in a bulk data transfer, in accordance with an embodiment;

FIG. 50 illustrates a Sendlnit message that may be used to initiate thecommunicative connection by the sender of FIG. 49, in accordance with anembodiment;

FIG. 51 illustrates a transfer control field of the Sendlnit message ofFIG. 50, in accordance with an embodiment;

FIG. 52 illustrates a range control field of the Sendlnit message ofFIG. 51, in accordance with an embodiment;

FIG. 53 illustrates a SendAccept message that may be used to accept acommunicative connection proposed by the Sendlnit message of FIG. 50sent by the sender of FIG. 50, in accordance with an embodiment;

FIG. 54 illustrates a SendReject message that may be used to reject acommunicative connection proposed by the Sendlnit message of FIG. 50sent by the sender of FIG. 50, in accordance with an embodiment;

FIG. 55 illustrates a ReceiveAccept message that may be used to accept acommunicative connection proposed by the receiver of FIG. 50, inaccordance with an embodiment;

FIG. 56 is a block diagram of an example of an IPv6 packet header usingan Extended Unique Local Address (EULA), in accordance with anembodiment;

FIG. 57 is a block diagram of an example of communicating an IPv6 packethaving the IPv6 packet of FIG. 56 through a fabric topology having twonetworks, in accordance with an embodiment;

FIG. 58 is a flowchart of a method for efficiently communicating theIPv6 packet through the fabric of FIG. 57 using the IPv6 packet headerof FIG. 56, in accordance with an embodiment;

FIG. 59 is a flowchart of a method for selecting an efficient transportprotocol over which to send a message based at least in part on one ormore reliability factors, in accordance with an embodiment;

FIG. 60 is a diagram illustrating a use case of a fabric of devices inwhich one device invokes a method on another device, in accordance withan embodiment;

FIG. 61 is a diagram illustrating a use case of a fabric of devices inwhich an alarm message is propagated through a number of low-power,sleepy devices, in accordance with an embodiment;

FIGS. 62-64 are flowcharts of a method for introducing a new device intoa fabric of devices, in accordance with an embodiment; and

FIGS. 65-67 are flowcharts of another method for introducing a newdevice into a fabric of devices, in accordance with an embodiment.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will bedescribed below. These described embodiments are only examples of thepresently disclosed techniques. Additionally, in an effort to provide aconcise description of these embodiments, all features of an actualimplementation may not be described in the specification. It should beappreciated that in the development of any such actual implementation,as in any engineering or design project, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one implementation toanother. Moreover, it should be appreciated that such a developmenteffort might be complex and time consuming, but may nevertheless be aroutine undertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments of the presentdisclosure, the articles “a,” “an,” and “the” are intended to mean thatthere are one or more of the elements. The terms “comprising,”“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements.Additionally, it should be understood that references to “oneembodiment” or “an embodiment” of the present disclosure are notintended to be interpreted as excluding the existence of additionalembodiments that also incorporate the recited features.

As used herein the term “HVAC” includes systems providing both heatingand cooling, heating only, cooling only, as well as systems that provideother occupant comfort and/or conditioning functionality such ashumidification, dehumidification and ventilation.

As used herein the terms power “harvesting,” “sharing” and “stealing,”when referring to home devices, refer to deriving power from a powertransformer through the equipment load without using a direct or commonwire source directly from the transformer.

As used herein the term “thermostat” means a device or system forregulating parameters such as temperature and/or humidity within atleast a part of an enclosure. The term “thermostat” may include acontrol unit for a heating and/or cooling system or a component part ofa heater or air conditioner. As used herein the term “thermostat” canalso refer generally to a versatile sensing and control unit (VSCU unit)that is configured and adapted to provide sophisticated, customized,energy-saving HVAC control functionality while at the same time beingvisually appealing, non-intimidating, elegant to behold, anddelightfully easy to use.

As used herein, the term “hazard detector” refers to any home devicethat can detect evidence of fire (e.g., smoke, heat, carbon monoxide)and/or other hazardous conditions (e.g., extreme temperatures, buildupof dangerous gases).

This disclosure relates to efficient communication that may be used bydevices communicating with each other in a home environment. Theefficient communication of this disclosure may enable a fabric ofdevices and/or services to communicate in the home environment. Indeed,consumers living in homes may find it useful to coordinate theoperations of various devices within their home such that all of theirdevices are operated efficiently. For example, a thermostat device maybe used to detect a temperature of a home and coordinate the activity ofother devices (e.g., lights) based on the detected temperature. Thethermostat device may detect a temperature that may indicate that thetemperature outside the home corresponds to daylight hours. Thethermostat device may then convey to the light device that there may bedaylight available to the home and that thus the light should turn off.In another example, a smart hazard detector may be able to detectenvironmental conditions that indicate occupancy. The thermostat devicemay query the hazard detector for these environmental conditions andvary its operation accordingly. In addition to efficiency, consumers maygenerally prefer user-friendly devices that involve a minimum amount ofset up or initialization. That is, consumers may generally preferdevices that are fully operational after performing a few numberinitialization steps, especially those that may be performed by almostany individual regardless of age or technical expertise.

To effectively and efficiently communicate data between each otherwithin the home environment, the devices may use a fabric network thatincludes one or more logical networks to manage communication betweenthe devices. That is, the efficient fabric network may enable numerousdevices within a home to communicate with each other using one or morelogical networks. The fabric network may be supported by an efficientcommunication scheme involving, for example, an efficient network layer,an efficient platform layer, and/or an efficient application layer tomanage communication. The fabric network may support Internet Protocolversion 6 (IPv6) communication such that each connected device may havea unique local address (ULA). In some examples, the IPv6 communicationsmay employ an Extended Unique Local Address (EULA). Moreover, to enableeach device to integrate with a home, it may be useful for each deviceto communicate within the network using low amounts of power. That is,by enabling devices to communicate using low power, the devices may beplaced anywhere in a home without being coupled to a continuous powersource (e.g., battery-powered).

On a relatively lower layer of the communication protocol (e.g., thenetwork layer), the fabric efficient network layer may establish acommunication network in which numerous devices within a home maycommunicate with each other via a wireless mesh network. Thecommunication network may support Internet Protocol version 6 (IPv6)communication such that each connected device may have a unique InternetProtocol (IP) address. Moreover, to enable each device to integrate witha home, it may be useful for each device to communicate within thenetwork using low amounts of power. That is, by enabling devices tocommunicate using low power, the devices may be placed anywhere in ahome without being coupled to a continuous power source.

The efficient network layer may thus establish a procedure in which datamay be transferred between two or more devices such that theestablishment of the communication network involves little user input,the communication between devices involves little energy, and thecommunication network, itself, is secure. In one embodiment, theefficient network layer may be an IPv6-based communication network thatemploys Routing Information Protocol-Next Generation (RIPng) as itsrouting mechanism and a Datagram Transport Layer Security (DTLS)protocol as its security mechanism. As such, the efficient network layermay provide a simple means for adding or removing devices to a homewhile protecting the information communicated between the connecteddevices.

On relatively higher layers of the communication protocol (e.g., theplatform and/or application layers), the fabric of devices may becreated and maintained. These layers may enable parametric softwareupdates and status reports throughout the fabric. These layers may alsoprovide communication that may be aware of certain network powerconstraints, such as the power constraints of “sleepy” orbattery-powered devices, and may communicate messages with these factorsin mind.

As such, embodiments of this disclosure relate to systems and methods afabric network that includes one or more logical networks that enablesdevices connected to the fabric to communicate with each other using alist of protocols and/or profiles known to the devices. Thecommunications between the devices may follow a typical message formatthat enables the devices to understand communications between thedevices regardless of which logical networks the communicating devicesare connected to in the fabric. Within the message format, a payload ofdata may be included for the receiving device to store and/or process.The format and the contents of the payload may vary according to aheader within the payload that indicates a profile (including one ormore protocols) and/or a type of message that is being sent according tothe profile.

According to some embodiments, two or more devices in a fabric maycommunicate using status reporting protocols or profiles. For example,in certain embodiments, a status reporting protocol or schema may beincluded in a core profile that is available to devices connected to thefabric. Using the status reporting protocol, devices may send or requeststatus information to or from other devices in the fabric.

Similarly, in certain embodiments, two or more devices in a fabric maycommunicate using update software protocols or profiles. In someembodiments, the update software protocol or schema may be included in acore profile that is available to devices connected to the fabric. Usingthe update software protocol, devices may request, send, or notify thepresence of updates within the fabric.

In certain embodiments, two or more devices in a fabric may communicateusing data management protocols or profiles. In some embodiments, thedata management protocol or schema may be included in a core profilethat is available to devices connected to the fabric. Using the updatedata management protocol, devices may request, view, or tracknode-resident information that is stored in other devices.

Furthermore, in certain embodiments, two or more devices in a fabric maytransfer data using bulk data transfer protocols or profiles. In someembodiments, the bulk data transfer protocol or schema may be includedin a core profile that is available to devices connected to the fabric.Using the bulk data transfer protocol, devices may initiate, send, orreceive bulk data using any logical networks in the fabric. In certainembodiments, either a sending or a receiving device using the bulk datatransfer protocol may be able to “drive” a synchronous transfer betweenthe devices. In other embodiments, the bulk transfer may be performedwith an asynchronous transfer.

Fabric Introduction

By way of introduction, FIG. 1 illustrates an example of a generaldevice 10 that may that may communicate with other like devices within ahome environment. In one embodiment, the device 10 may include one ormore sensors 12, a user-interface component 14, a power supply 16 (e.g.,including a power connection and/or battery), a network interface 18, aprocessor 20, and the like. Particular sensors 12, user-interfacecomponents 14, and power-supply configurations may be the same orsimilar with each devices 10. However, it should be noted that in someembodiments, each device 10 may include particular sensors 12,user-interface components 14, power-supply configurations, and the likebased on a device type or model.

The sensors 12, in certain embodiments, may detect various propertiessuch as acceleration, temperature, humidity, water, supplied power,proximity, external motion, device motion, sound signals, ultrasoundsignals, light signals, fire, smoke, carbon monoxide,global-positioning-satellite (GPS) signals, radio-frequency (RF), otherelectromagnetic signals or fields, or the like. As such, the sensors 12may include temperature sensor(s), humidity sensor(s), hazard-relatedsensor(s) or other environmental sensor(s), accelerometer(s),microphone(s), optical sensors up to and including camera(s) (e.g.,charged coupled-device or video cameras), active or passive radiationsensors, GPS receiver(s) or radiofrequency identification detector(s).While FIG. 1 illustrates an embodiment with a single sensor, manyembodiments may include multiple sensors. In some instances, the device10 may includes one or more primary sensors and one or more secondarysensors. Here, the primary sensor(s) may sense data central to the coreoperation of the device (e.g., sensing a temperature in a thermostat orsensing smoke in a smoke detector), while the secondary sensor(s) maysense other types of data (e.g., motion, light or sound), which can beused for energy-efficiency objectives or smart-operation objectives.

One or more user-interface components 14 in the device 10 may receiveinput from the user and/or present information to the user. The receivedinput may be used to determine a setting. In certain embodiments, theuser-interface components may include a mechanical or virtual componentthat responds to the user's motion. For example, the user canmechanically move a sliding component (e.g., along a vertical orhorizontal track) or rotate a rotatable ring (e.g., along a circulartrack), or the user's motion along a touchpad may be detected. Suchmotions may correspond to a setting adjustment, which can be determinedbased on an absolute position of a user-interface component 104 or basedon a displacement of a user-interface components 104 (e.g., adjusting aset point temperature by 1 degree F. for every 10° rotation of arotatable-ring component). Physically and virtually movableuser-interface components can allow a user to set a setting along aportion of an apparent continuum. Thus, the user may not be confined tochoose between two discrete options (e.g., as would be the case if upand down buttons were used) but can quickly and intuitively define asetting along a range of possible setting values. For example, amagnitude of a movement of a user-interface component may be associatedwith a magnitude of a setting adjustment, such that a user maydramatically alter a setting with a large movement or finely tune asetting with s small movement.

The user-interface components 14 may also include one or more buttons(e.g., up and down buttons), a keypad, a number pad, a switch, amicrophone, and/or a camera (e.g., to detect gestures). In oneembodiment, the user-interface component 14 may include aclick-and-rotate annular ring component that may enable the user tointeract with the component by rotating the ring (e.g., to adjust asetting) and/or by clicking the ring inwards (e.g., to select anadjusted setting or to select an option). In another embodiment, theuser-interface component 14 may include a camera that may detectgestures (e.g., to indicate that a power or alarm state of a device isto be changed). In some instances, the device 10 may have one primaryinput component, which may be used to set a plurality of types ofsettings. The user-interface components 14 may also be configured topresent information to a user via, e.g., a visual display (e.g., athin-film-transistor display or organic light-emitting-diode display)and/or an audio speaker.

The power-supply component 16 may include a power connection and/or alocal battery. For example, the power connection may connect the device10 to a power source such as a line voltage source. In some instances,an AC power source can be used to repeatedly charge a (e.g.,rechargeable) local battery, such that the battery may be used later tosupply power to the device 10 when the AC power source is not available.

The network interface 18 may include a component that enables the device10 to communicate between devices. In one embodiment, the networkinterface 18 may communicate using an efficient network layer as part ofits Open Systems Interconnection (OSI) model. In one embodiment, theefficient network layer, which will be described in more detail belowwith reference to FIG. 5, may enable the device 10 to wirelesslycommunicate IPv6-type data or traffic using a RIPng routing mechanismand a DTLS security scheme. As such, the network interface 18 mayinclude a wireless card or some other transceiver connection.

The processor 20 may support one or more of a variety of differentdevice functionalities. As such, the processor 20 may include one ormore processors configured and programmed to carry out and/or cause tobe carried out one or more of the functionalities described herein. Inone embodiment, the processor 20 may include general-purpose processorscarrying out computer code stored in local memory (e.g., flash memory,hard drive, random access memory), special-purpose processors orapplication-specific integrated circuits, combinations thereof, and/orusing other types of hardware/firmware/software processing platforms.Further, the processor 20 may be implemented as localized versions orcounterparts of algorithms carried out or governed remotely by centralservers or cloud-based systems, such as by virtue of running a Javavirtual machine (JVM) that executes instructions provided from a cloudserver using Asynchronous JavaScript and XML (AJAX) or similarprotocols. By way of example, the processor 20 may detect when alocation (e.g., a house or room) is occupied, up to and includingwhether it is occupied by a specific person or is occupied by a specificnumber of people (e.g., relative to one or more thresholds). In oneembodiment, this detection can occur, e.g., by analyzing microphonesignals, detecting user movements (e.g., in front of a device),detecting openings and closings of doors or garage doors, detectingwireless signals, detecting an IP address of a received signal,detecting operation of one or more devices within a time window, or thelike. Moreover, the processor 20 may include image recognitiontechnology to identify particular occupants or objects.

In certain embodiments, the processor 20 may also include a high-powerprocessor and a low-power processor. The high-power processor mayexecute computational intensive operations such as operating theuser-interface component 14 and the like. The low-power processor, onthe other hand, may manage less complex processes such as detecting ahazard or temperature from the sensor 12. In one embodiment, thelow-power processor may wake or initialize the high-power processor forcomputationally intensive processes.

In some instances, the processor 20 may predict desirable settingsand/or implement those settings. For example, based on the presencedetection, the processor 20 may adjust device settings to, e.g.,conserve power when nobody is home or in a particular room or to accordwith user preferences (e.g., general at-home preferences oruser-specific preferences). As another example, based on the detectionof a particular person, animal or object (e.g., a child, pet or lostobject), the processor 20 may initiate an audio or visual indicator ofwhere the person, animal or object is or may initiate an alarm orsecurity feature if an unrecognized person is detected under certainconditions (e.g., at night or when lights are off).

In some instances, devices may interact with each other such that eventsdetected by a first device influences actions of a second device. Forexample, a first device can detect that a user has pulled into a garage(e.g., by detecting motion in the garage, detecting a change in light inthe garage or detecting opening of the garage door). The first devicecan transmit this information to a second device via the efficientnetwork layer, such that the second device can, e.g., adjust a hometemperature setting, a light setting, a music setting, and/or asecurity-alarm setting. As another example, a first device can detect auser approaching a front door (e.g., by detecting motion or sudden lightpattern changes). The first device may, e.g., cause a general audio orvisual signal to be presented (e.g., such as sounding of a doorbell) orcause a location-specific audio or visual signal to be presented (e.g.,to announce the visitor's presence within a room that a user isoccupying).

By way of example, the device 10 may include a thermostat such as aNest® Learning Thermostat. Here, the thermostat may include sensors 12such as temperature sensors, humidity sensors, and the like such thatthe thermostat may determine present climate conditions within abuilding where the thermostat is disposed. The power-supply component 16for the thermostat may be a local battery such that the thermostat maybe placed anywhere in the building without regard to being placed inclose proximity to a continuous power source. Since the thermostat maybe powered using a local battery, the thermostat may minimize its energyuse such that the battery is rarely replaced.

In one embodiment, the thermostat may include a circular track that mayhave a rotatable ring disposed thereon as the user-interface component14. As such, a user may interact with or program the thermostat usingthe rotatable ring such that the thermostat controls the temperature ofthe building by controlling a heating, ventilation, and air-conditioning(HVAC) unit or the like. In some instances, the thermostat may determinewhen the building may be vacant based on its programming. For instance,if the thermostat is programmed to keep the HVAC unit powered off for anextended period of time, the thermostat may determine that the buildingwill be vacant during this period of time. Here, the thermostat may beprogrammed to turn off light switches or other electronic devices whenit determines that the building is vacant. As such, the thermostat mayuse the network interface 18 to communicate with a light switch devicesuch that it may send a signal to the light switch device when thebuilding is determined to be vacant. In this manner, the thermostat mayefficiently manage the energy use of the building.

Keeping the foregoing in mind, FIG. 2 illustrates a block diagram of ahome environment 30 in which the device 10 of FIG. 1 may communicatewith other devices via the efficient network layer. The depicted homeenvironment 30 may include a structure 32 such as a house, officebuilding, garage, or mobile home. It will be appreciated that devicescan also be integrated into a home environment that does not include anentire structure 32, such as an apartment, condominium, office space, orthe like. Further, the home environment 30 may control and/or be coupledto devices outside of the actual structure 32. Indeed, several devicesin the home environment 30 need not physically be within the structure32 at all. For example, a device controlling a pool heater 34 orirrigation system 36 may be located outside of the structure 32.

The depicted structure 32 includes a number of rooms 38, separated atleast partly from each other via walls 40. The walls 40 can includeinterior walls or exterior walls. Each room 38 can further include afloor 42 and a ceiling 44. Devices can be mounted on, integrated withand/or supported by the wall 40, the floor 42, or the ceiling 44.

The home environment 30 may include a plurality of devices, includingintelligent, multi-sensing, network-connected devices that may integrateseamlessly with each other and/or with cloud-based server systems toprovide any of a variety of useful home objectives. One, more or each ofthe devices illustrated in the home environment 30 may include one ormore sensors 12, a user interface 14, a power supply 16, a networkinterface 18, a processor 20 and the like.

Example devices 10 may include a network-connected thermostat 46 such asNest® Learning Thermostat—1st Generation T100577 or Nest® LearningThermostat—2nd Generation T200577 by Nest Labs, Inc. The thermostat 46may detect ambient climate characteristics (e.g., temperature and/orhumidity) and control a heating, ventilation and air-conditioning (HVAC)system 48. Another example device 10 may include a hazard detection unit50 such as a hazard detection unit by Nest®. The hazard detection unit50 may detect the presence of a hazardous substance and/or a hazardouscondition in the home environment 30 (e.g., smoke, fire, or carbonmonoxide). Additionally, an entryway interface devices 52, which can betermed a “smart doorbell”, can detect a person's approach to ordeparture from a location, control audible functionality, announce aperson's approach or departure via audio or visual means, or controlsettings on a security system (e.g., to activate or deactivate thesecurity system).

In certain embodiments, the device 10 may include a light switch 54 thatmay detect ambient lighting conditions, detect room-occupancy states,and control a power and/or dim state of one or more lights. In someinstances, the light switches 54 may control a power state or speed of afan, such as a ceiling fan.

Additionally, wall plug interfaces 56 may detect occupancy of a room orenclosure and control supply of power to one or more wall plugs (e.g.,such that power is not supplied to the plug if nobody is at home). Thedevice 10 within the home environment 30 may further include anappliance 58, such as refrigerators, stoves and/or ovens, televisions,washers, dryers, lights (inside and/or outside the structure 32),stereos, intercom systems, garage-door openers, floor fans, ceilingfans, whole-house fans, wall air conditioners, pool heaters 34,irrigation systems 36, security systems, and so forth. Whiledescriptions of FIG. 2 may identify specific sensors and functionalitiesassociated with specific devices, it will be appreciated that any of avariety of sensors and functionalities (such as those describedthroughout the specification) may be integrated into the device 10.

In addition to containing processing and sensing capabilities, each ofthe example devices described above may be capable of datacommunications and information sharing with any other device, as well asto any cloud server or any other device that is network-connectedanywhere in the world. In one embodiment, the devices 10 may send andreceive communications via the efficient network layer that will bediscussed below with reference to FIG. 5. In one embodiment, theefficient network layer may enable the devices 10 to communicate witheach other via a wireless mesh network. As such, certain devices mayserve as wireless repeaters and/or may function as bridges betweendevices in the home environment that may not be directly connected(i.e., one hop) to each other.

In one embodiment, a wireless router 60 may further communicate with thedevices 10 in the home environment 30 via the wireless mesh network. Thewireless router 60 may then communicate with the Internet 62 such thateach device 10 may communicate with a central server or acloud-computing system 64 through the Internet 62. The central server orcloud-computing system 64 may be associated with a manufacturer, supportentity or service provider associated with a particular device 10. Assuch, in one embodiment, a user may contact customer support using adevice itself rather than using some other communication means such as atelephone or Internet-connected computer. Further, software updates canbe automatically sent from the central server or cloud-computing system64 to the devices (e.g., when available, when purchased, or at routineintervals).

By virtue of network connectivity, one or more of the devices 10 mayfurther allow a user to interact with the device even if the user is notproximate to the device. For example, a user may communicate with adevice using a computer (e.g., a desktop computer, laptop computer, ortablet) or other portable electronic device (e.g., a smartphone) 66. Awebpage or application may receive communications from the user andcontrol the device 10 based on the received communications. Moreover,the webpage or application may present information about the device'soperation to the user. For example, the user can view a current setpoint temperature for a device and adjust it using a computer that maybe connected to the Internet 62. In this example, the thermostat 46 mayreceive the current set point temperature view request via the wirelessmesh network created using the efficient network layer.

In certain embodiments, the home environment 30 may also include avariety of non-communicating legacy appliances 68, such as oldconventional washer/dryers, refrigerators, and the like which can becontrolled, albeit coarsely (ON/OFF), by virtue of the wall pluginterfaces 56. The home environment 30 may further include a variety ofpartially communicating legacy appliances 70, such as infra-red (IR)controlled wall air conditioners or other IR-controlled devices, whichcan be controlled by IR signals provided by the hazard detection units50 or the light switches 54.

As mentioned above, each of the example devices 10 described above mayestablish a wireless mesh network such that data may be communicated toeach device 10. Keeping the example devices of FIG. 2 in mind, FIG. 3illustrates an example wireless mesh network 80 that may be employed tofacilitate communication between some of the example devices describedabove. As shown in FIG. 3, the thermostat 46 may have a direct wirelessconnection to the plug interface 56, which may be wirelessly connectedto the hazard detection unit 50 and to the light switch 54. In the samemanner, the light switch 54 may be wirelessly coupled to the appliance58 and the portable electronic device 66. The appliance 58 may just becoupled to the pool heater 34 and the portable electronic device 66 mayjust be coupled to the irrigation system 36. The irrigation system 36may have a wireless connection to the entryway interface device 52. Eachdevice in the wireless mesh network 80 of FIG. 3 may correspond to anode within the wireless mesh network 80. In one embodiment, theefficient network layer may specify that each node transmit data using aRIPng protocol and a DTLS protocol such that data may be securelytransferred to a destination node via a minimum number of hops betweennodes.

Generally, the efficient network layer may be part of an Open SystemsInterconnection (OSI) model 90 as depicted in FIG. 4. The OSI model 90illustrates functions of a communication system with respect toabstraction layers. That is, the OSI model may specify a networkingframework or how communications between devices may be implemented. Inone embodiment, the OSI model may include six layers: a physical layer92, a data link layer 94, a network layer 96, a transport layer 98, aplatform layer 100, and an application layer 102. Generally, each layerin the OSI model 90 may serve the layer above it and may be served bythe layer below it. In at least some embodiments, a higher layer may beagnostic to technologies used in lower layers. For example, in certainembodiments, the platform layer 100 may be agnostic to the network typeused in the network layer 96.

Keeping this in mind, the physical layer 92 may provide hardwarespecifications for devices that may communicate with each other. Assuch, the physical layer 92 may establish how devices may connect toeach other, assist in managing how communication resources may be sharedbetween devices, and the like.

The data link layer 94 may specify how data may be transferred betweendevices. Generally, the data link layer 94 may provide a way in whichdata packets being transmitted may be encoded and decoded into bits aspart of a transmission protocol.

The network layer 96 may specify how the data being transferred to adestination node is routed. The network layer 96 may also provide asecurity protocol that may maintain the integrity of the data beingtransferred.

The transport layer 98 may specify a transparent transfer of the datafrom a source node to a destination node. The transport layer 98 mayalso control how the transparent transfer of the data remains reliable.As such, the transport layer 98 may be used to verify that data packetsintended to transfer to the destination node indeed reached thedestination node. Example protocols that may be employed in thetransport layer 98 may include Transmission Control Protocol (TCP) andUser Datagram Protocol (UDP).

The platform layer 100 may establish connections between devicesaccording to the protocol specified within the transport layer 98. Theplatform layer 100 may also translate the data packets into a form thatthe application layer 102 may use. The application layer 102 may supporta software application that may directly interface with the user. Assuch, the application layer 102 may implement protocols defined by thesoftware application. For example, the software application may provideserves such as file transfers, electronic mail, and the like.

Efficient Network Layer

Referring now to FIG. 5, in one embodiment, the network layer 96 and thetransport layer 98 may be configured in a certain manner to form anefficient low power wireless personal network (ELoWPAN) 110. In oneembodiment, the ELoWPAN 110 may be based on an IEEE 802.15.4 network,which may correspond to low-rate wireless personal area networks(LR-WPANs). The ELoWPAN 110 may specify that the network layer 96 mayroute data between the devices 10 in the home environment 30 using acommunication protocol based on Internet Protocol version 6 (IPv6). Assuch, each device 10 may include a 128-bit IPv6 address that may provideeach device 10 with a unique address to use to identify itself over theInternet, a local network around the home environment 30, or the like.

In one embodiment, the network layer 96 may specify that data may berouted between devices using Routing Information Protocol-NextGeneration (RIPng). RIPng is a routing protocol that routes data via awireless mesh network based on a number of hops between the source nodeand the destination node. That is, RIPng may determine a route to thedestination node from the source node that employs the least number ofhops when determining how the data will be routed. In addition tosupporting data transfers via a wireless mesh network, RIPng is capableof supporting IPv6 networking traffic. As such, each device 10 may use aunique IPv6 address to identify itself and a unique IPv6 address toidentify a destination node when routing data. Additional details withregard to how the RIPng may send data between nodes will be describedbelow with reference to FIG. 6.

As mentioned above, the network layer 96 may also provide a securityprotocol that may manage the integrity of the data being transferred.Here, the efficient network layer may secure data transferred betweendevices using a Datagram Transport Layer Security (DTLS) protocol.Generally, Transport Layer Security (TLS) protocol is commonly used toprotect data transfers via the Internet. However, in order for the TLSprotocol to be effective, the TLS protocol may transport data using areliable transport channel such as Transmission Control Protocol (TCP).DTLS provides a similar level of security for transferred data whilesupporting unreliable transport channels such as User Datagram Protocol(UDP). Additional details with regard to the DTLS protocol will bedescribed below with reference to FIGS. 8 and 9.

The network layer 96 depicted in FIG. 5 is characterized herein as theefficient network layer mentioned above. That is, the efficient networklayer routes IPv6 data using RIPng and secures the routed data using theDTLS protocol. Since the efficient network layer uses the DTLS protocolto secure data transfer between devices, the transport layer 98 maysupport TCP and UDP transfer schemes for the data.

Referring now to FIG. 6, FIG. 6 depicts a flowchart of a method 120 thatmay be used for determining a routing table for each device 10 in thewireless mesh network 80 of FIG. 3 using RIPng. The method 120 may beperformed by each device 10 in the home environment 30 such that eachdevice 10 may generate a routing table that indicates how each node inthe wireless mesh network 80 may be connected to each other. As such,each device 10 may independently determine how to route data to adestination node. In one embodiment, the processor 20 of the device 10may perform the method 120 using the network interface 18. As such, thedevice 10 may send data associated with the sensor 12 or determined bythe processor 18 to other devices 10 in the home environment 30 vianetwork interface 18.

The following discussion of the method 120 will be described withreference to FIGS. 7A-7D to clearly illustrate various blocks of themethod 120. Keeping this in mind and referring to both FIG. 6 and FIG.7A, at block 122, the device 10 may send a request 132 to any otherdevice 10 that may be directly (i.e., zero hops) to the requestingdevice 10. The request 132 may include a request for all of the routinginformation from the respective device 10. For example, referring toFIG. 7A, the device 10 at node 1 may send the request 132 to the device10 at node 2 to send all of the routes (i.e., N2's routes) included innode 2's memory.

At block 124, the requesting device 10 may receive a message from therespective device 10 that may include all of the routes included in therespective memory of the respective device 10. The routes may beorganized in a routing table that may specify how each node in thewireless mesh network 80 may be connected to each other. That is, therouting table may specify which intermediate nodes data may betransferred to such that data from a source node to a destination node.Referring back to the example above and to FIG. 7B, in response to node1's request for N2's routes, at block 124, node 2 may send node 1 all ofthe routes (N2's routes 144) included in the memory or storage of node2. In one embodiment, each node of the wireless mesh network 80 may sendthe request 132 to its adjacent node as shown in FIG. 7A. In response,each node may then send its routes to its adjacent node as shown in FIG.7B. For instance, FIG. 7B illustrates how each node sends its route datato each adjacent node as depicted with N1's routes 142, N2's routes 144,N3's routes 146, N4's routes 148, N5's routes 150, N6's routes 152, N7'sroutes 154, N8's routes 156, and N9's routes 158.

Initially, each node may know the nodes in which it may have a directconnection (i.e., zero hops). For example, initially, node 2 may justknow that it is directly connected to node 1, node 3, and node 4.However, after receiving N1's routes 142, N3's routes 146, and N4'sroutes 148, the processor 20 of node 2 may build a routing table thatincludes all of the information included with N1's routes 142, N3'sroutes 146, and N4's routes 148. As such, the next time node 2 receivesa request for its routes or routing table (i.e., N2's routes 144), node2 may send a routing table that includes N1's routes 142, N2's routes,N3's routes 146, and N4's routes 148.

Keeping this in mind and referring back to FIG. 6, at block 126, therequesting device 10 may update its local routing table to include therouting information received from the adjacent device 10. In certainembodiments, each device 10 may perform the method 120 periodically suchthat each device 10 includes an updated routing table that characterizeshow each node in the wireless mesh network 80 may be connected to eachother. As mentioned above, each time the method 120 is performed, eachdevice 10 may receive additional information from its adjacent device 10if the adjacent device 10 updated its routing table with the informationreceived from its adjacent devices. As a result, each device 10 mayunderstand how each node in the wireless mesh network 80 may beconnected to each other.

FIG. 7C, for example, illustrates a routing table 172 that may have beendetermined by the device 10 at node 1 using the method 120. In thisexample, the routing table 172 may specify each node in the wirelessmesh network 80 as a destination node, the intermediate nodes betweennode 1 and each destination node, and a number of hops between node 1and the destination node. The number of hops corresponds to a number oftimes that the data being sent to the destination node may be forwardedto an intermediate node before reaching the destination node. Whensending data to a particular destination node, the RIPng routing schememay select a route that involves the least number of hops. For instance,if node 1 intended to send data to node 9, the RIPng routing schemewould route the data via nodes 2, 4, 5, and 8, which includes four hops,as opposed to routing the data via nodes 2, 4, 6, 7, and 8, includeincludes five hops.

By using the RIPng routing scheme, each device 10 may independentlydetermine how data should be routed to a destination node. Conventionalrouting schemes such as “Ripple” Routing Protocol (RPL) used in 6LoWPANdevices, on the other hand, may route data through a central node, whichmay be the only node that knows the structure of the wireless meshnetwork. More specifically, the RPL protocol may create a wireless meshnetwork according to a directed acyclic graph (DAG), which may bestructured as a hierarchy. Located at the top of this hierarchy mayinclude a border router, which may periodically multicasts requests tolower level nodes to determine a rank for each of the node'sconnections. In essence, when data is transferred from a source node toa destination node, the data may be transferred up the hierarchy ofnodes and then back down to the destination node. In this manner, thenodes located higher up the hierarchy may route data more often than thenodes located lower in the hierarchy. Moreover, the border router of theRPL system may also be operating more frequently since it controls howdata will be routed via the hierarchy. In the conventional RPL system,in contrast to the RIPng system taught here, some nodes may route dataon a more frequent basis simply due to its location within the hierarchyand not due to its location with respect to the source node and thedestination node. These nodes that route data more often under the RPLsystem may consume more energy and thus may not be a suitable toimplement with the devices 10 in the home environment 30 that operateusing low power. Moreover, as mentioned above, if the border router orany other higher-level node of the RPL system corresponds to thethermostat 46, the increased data routing activity may increase the heatproduced within the thermostat 46. As a result, the temperature readingof the thermostat 46 may incorrectly represent the temperature of thehome environment 30. Since other devices 10 may perform specificoperations based on the temperature reading of the thermostat 46, andsince the thermostat 46 may send commands to various devices 10 based onits temperature reading, it may be beneficial to ensure that thetemperature reading of the thermostat 46 is accurate.

In addition to ensuring that none of the devices 10 routes data adisproportionate amount of times, by using the RIPng routing scheme, newdevices 10 may be added to the wireless mesh network with minimum effortby the user. For example, FIG. 7D illustrates a new node 10 being addedto the wireless mesh network 80. In certain embodiments, once the node10 establishes a connection to the wireless mesh network 80 (e.g., vianode 4), the device 10 that corresponds to node 10 may perform themethod 120 described above to determine how data may be routed to eachnode in the wireless mesh network 80. If each node in the wireless meshnetwork 80 has already performed the method 120 multiple times, thedevice 10 at node 10 may receive the entire routing structure of thewireless mesh network 80 from the device 10 at node 4. In the samemanner, devices 10 may be removed from the wireless mesh network 80 andeach node may update its routing table with relative ease by performingthe method 120 again.

After establishing a routing scheme using the RIPng routing scheme,ELoWPAN 110 may employ a DTLS protocol to secure data communicationsbetween each device 10 in the home environment 30. As mentioned above,by using the DTLS protocol instead of a TLS protocol, ELoWPAN 110 mayenable the transport layer 98 to send data via TCP and UDP. Although UDPmay be generally more unreliable as compared to TCP, UDP data transfersemploys a simple communication scheme without having dedicatedtransmissions channels or data paths set up prior to use. As such, newdevices 10 added to the wireless mesh network 80 may use UDP datatransfers to effectively communicate to other devices 10 in the wirelessmesh network more quickly. Moreover, UDP data transfers generally useless energy by the device 10 that is sending or forwarding the datasince there is no guarantee of delivery. As such, the devices 10 maysend non-critical data (e.g., presence of a person in a room) using theUDP data transfer, thereby saving energy within the device 10. However,critical data (e.g., smoke alarm) may be sent via TCP data transfer toensure that the appropriate party receives the data. To reiterate, usinga DTLS security scheme with ELoWPAN 110 may help facilitate UDP and TCPdata transfers.

Keeping the foregoing in mind, ELoWPAN 110 may employ the DTLS protocolto secure the data communicated between the devices 10. In oneembodiment, the DTLS protocol may secure data transfers using ahandshake protocol. Generally, the handshake protocol may authenticateeach communicating device using a security certificate that may beprovided by each device 10. FIG. 8 illustrates an example of amanufacturing process 190 that depicts how the security certificate maybe embedded within the device 10.

Referring to FIG. 8, a trusted manufacturer 192 of the device 10 may beprovided with a number of security certificates that it may use for eachmanufactured device. As such, while producing a device 10 that may beused in the home environment 30 and coupled to the wireless mesh network80, the trusted manufacturer 192 may embed a certificate 194 into thedevice 10 during the manufacturing process 190. That is, the certificate194 may be embedded into the hardware of the device 10 duringmanufacturing of the device 10. The certificate 194 may include a publickey, a private key, or other cryptographic data that may be used toauthenticate different communicating devices within the wireless meshnetwork 80. As a result, once a user receives the device 10, the usermay integrate the device 10 into the wireless mesh network 80 withoutinitializing or registering the device 10 with a central security nodeor the like.

In conventional data communication security protocols such as Protocolfor Carrying Authentication for Network Access (PANA) used in 6LoWPANdevices, each device 10 may authenticate itself with a specific node(i.e., authentication agent). As such, before data is transferredbetween any two devices 10, each device 10 may authenticate itself withthe authentication agent node. The authentication agent node may thenconvey the result of the authentication to an enforcement point node,which may be co-located with the authentication agent node. Theenforcement point node may then establish a data communication linkbetween the two devices 10 if the authentications are valid. Moreover,in PANA, each device 10 may communicate with each other via anenforcement point node, which may verify that the authentication foreach device 10 is valid.

As such, by using the DTLS protocol rather than PANA to secure datatransfers between nodes, the efficient network layer may avoid using anauthorization agent node, an enforcement point node, or bothexcessively. That is, no one node using the efficient network layer maybe processing authentication data for each data transfer between nodesin the wireless mesh network. As a result, the nodes using the efficientnetwork layer may conserve more energy as compared to the authorizationagent node or the enforcement point node in the PANA protocol system.

Keeping this in mind, FIG. 9 illustrates an example handshake protocol200 that may be used between devices 10 when transferring data betweeneach other. As shown in FIG. 9, the device 10 at node 1 may send amessage 202 to the device 10 at node 2. The message 202 may be a hellomessage that may include cipher suites, hash and compression algorithms,and a random number. The device 10 at node 2 may then respond with amessage 204, which may verify that the device 10 at node 2 received themessage 202 from the device 10 at node 1.

After establishing the connection between node 1 and node 2, the deviceat node 1 may again send the message 202 to the device 10 at node 2. Thedevice 10 at node 2 may then respond with a message 208, which mayinclude a hello message from node 2, a certificate 194 from node 2, akey exchange from node 2, and a certificate request for node 1. Thehello message in the message 208 may include cipher suites, hash andcompression algorithms, and a random number. The certificate 194 may bethe security certificate embedded within the device 10 by the trustedmanufacturer 192 as discussed above with reference to FIG. 8. The keyexchange may include a public key, a private key, or other cryptographicinformation that may be used to determine a secret key for establishinga communication channel between the two nodes. In one embodiment, thekey exchange may be stored in the certificate 194 of the correspondingdevice 10 located at the respective node.

In response to the message 208, the device 10 at node 1 may send message210 that may include a certificate 194 from node 1, a key exchange fromnode 1, a certificate verification of node 2, and a change cipher specfrom node 1. In one embodiment, the device 10 at node 1 may use thecertificate 194 of node 2 and the key exchange from node 1 to verify thecertificate 194 of node 2. That is, the device 10 at node 1 may verifythat the certificate 194 received from node 2 is valid based on thecertificate 194 of node 2 and the key exchange from node 1. If thecertificate 194 from node 2 is valid, the device 10 at node 1 may sendthe change cipher spec message to the device 10 at node 2 to announcethat the communication channel between the two nodes is secure.

Similarly, upon receiving the message 210, the device 10 at node 2 mayuse the certificate 194 of node 1 and the key exchange from node 2 toverify the certificate 194 of node 1. That is, the device 10 at node 2may verify that the certificate 194 received from node 1 is valid basedon the certificate 194 of node 1 and the key exchange from node 2. Ifthe certificate 194 from node 1 is valid, the device 10 at node 2 mayalso send the change cipher spec message to the device 10 at node 1 toannounce that the communication channel between the two nodes is secure.

After establishing that the communication channel is secure, the device10 at node 1 may send a group-wise network key 214 to the device 10 atnode 2. The group-wise network key 214 may be associated with theELoWPAN 110. In this manner, as new devices join the ELoWPAN 110,devices previously authorized to communicate within the ELoWPAN 110 mayprovide the new devices access to the ELoWPAN 110. That is, the devicespreviously authorized to communicate within the ELoWPAN 110 may providethe group-wise network key 214 to the new devices, which may enable thenew devices to communicate with other devices in the ELoWPAN 110. Forexample, the group-wise network key 214 may be used to communicate withother devices that have been properly authenticated and that havepreviously provided with the group-wise network key 214. In oneembodiment, once the change cipher spec message has been exchangedbetween the device 10 at node 1 and the device 10 at node 2,identification information such as model number, device capabilities,and the like may be communicated between the devices. However, after thedevice 10 at node 2 receives the group-wise network key 214, additionalinformation such as data from sensors disposed on the device 10, dataanalysis performed by the device 10, and the like may be communicatedbetween devices.

By embedding the security certificate within the device 10 during themanufacturing process, the device 10 may not involve the user withestablishing security or authentication processes for the device 10.Moreover, since the device 10 may ensure that data is securelytransferred between nodes based on a handshake protocol as opposed to acentral authentication agent node, the security of the data transfers inthe wireless mesh network 80 may not rely on a single node for security.Instead, the efficient network layer may ensure that data may besecurely transferred between nodes even when some node becomesunavailable. As such, the efficient network layer may be much lessvulnerable to security issues since it does not rely on a single nodefor securing data messages.

Efficient Platform and/or Application Layers

Using the above-described ELowPAN 110 and/or any other suitable IPv6logical networks, efficient platform and/or application layers may beused to generate a fabric of devices in a home environment or similarenvironments. The fabric of devices may enable many generally localdevices to communicate, sharing data and information, invoking methodson one another, parametrically providing software updates through thenetwork, and generally communicating messages in an efficient,power-conscious way.

Fabric—Device Interconnection

As discussed above, a fabric may be implemented using one or moresuitable communications protocols, such as IPv6 protocols. In fact, thefabric may be partially or completely agnostic to the underlyingtechnologies (e.g., network types or communication protocols) used toimplement the fabric. Within the one or more communications protocols,the fabric may be implemented using one or more network types used tocommunicatively couple electrical devices using wireless or wiredconnections. For example, certain embodiments of the fabric may includeEthernet, WiFi, 802.15.4, ZigBee®, ISA100.11a, WirelessHART, MiWi™,power-line networks, and/or other suitable network types. Within thefabric devices (e.g., nodes) can exchange packets of information withother devices (e.g., nodes) in the fabric, either directly or viaintermediary nodes, such as intelligent thermostats, acting as IProuters. These nodes may include manufacturer devices (e.g., thermostatsand smoke detectors) and/or customer devices (e.g., phones, tablets,computers, etc.). Additionally, some devices may be “always on” andcontinuously powered using electrical connections. Other devices mayhave partially reduced power usage (e.g., medium duty cycle) using areduced/intermittent power connection, such as a thermostat or doorbellpower connection. Finally, some devices may have a short duty cycle andrun solely on battery power. In other words, in certain embodiments, thefabric may include heterogeneous devices that may be connected to one ormore sub-networks according to connection type and/or desired powerusage. FIGS. 10-12 illustrate three embodiments that may be used toconnect electrical devices via one or more sub-networks in the fabric.

A. Single Network Topology

FIG. 10 illustrates an embodiment of the fabric 1000 having a singlenetwork topology. As illustrated, the fabric 1000 includes a singlelogical network 1002. The network 1002 could include Ethernet, WiFi,802.15.4, power-line networks, and/or other suitable network types inthe IPv6 protocols. In fact, in some embodiments where the network 1002includes a WiFi or Ethernet network, the network 1002 may span multipleWiFi and/or Ethernet segments that are bridged at a link layer.

The network 1002 includes one or more nodes 1004, 1006, 1008, 1010,1012, 1014, and 1016, referred to collectively as 1004-1016. Althoughthe illustrated network 1002 includes seven nodes, certain embodimentsof the network 1002 may include one or more nodes interconnected usingthe network 1002. Moreover, if the network 1002 is a WiFi network, eachof the nodes 1004-1016 may be interconnected using the node 1016 (e.g.,WiFi router) and/or paired with other nodes using WiFi Direct (i.e.,WiFi P2P).

B. Star Network Topology

FIG. 11 illustrates an alternative embodiment of fabric 1000 as a fabric1018 having a star network topology. The fabric 1018 includes a hubnetwork 1020 that joins together two periphery networks 1022 and 1024.The hub network 1020 may include a home network, such as WiFi/Ethernetnetwork or power line network. The periphery networks 1022 and 1024 mayadditional network connection types different of different types thanthe hub network 1020. For example, in some embodiments, the hub network1020 may be a WiFi/Ethernet network, the periphery network 1022 mayinclude an 802.15.4 network, and the periphery network 1024 may includea power line network, a ZigBee® network, a ISA100.11a network, aWirelessHART, network, or a MiWi™ network. Moreover, although theillustrated embodiment of the fabric 1018 includes three networks,certain embodiments of the fabric 1018 may include any number ofnetworks, such as 2, 3, 4, 5, or more networks. In fact, someembodiments of the fabric 1018 include multiple periphery networks ofthe same type.

Although the illustrated fabric 1018 includes fourteen nodes, eachreferred to individually by reference numbers 1024-1052, respectively,it should be understood that the fabric 1018 may include any number ofnodes. Communication within each network 1020, 1022, or 1024, may occurdirectly between devices and/or through an access point, such as node1042 in a WiFi/Ethernet network. Communications between peripherynetwork 1022 and 1024 passes through the hub network 1020 usinginter-network routing nodes. For example, in the illustrated embodiment,nodes 1034 and 1036 are be connected to the periphery network 1022 usinga first network connection type (e.g., 802.15.4) and to the hub network1020 using a second network connection type (e.g., WiFi) while the node1044 is connected to the hub network 1020 using the second networkconnection type and to the periphery network 1024 using a third networkconnection type (e.g., power line). For example, a message sent fromnode 1026 to node 1052 may pass through nodes 1028, 1030, 1032, 1036,1042, 1044, 1048, and 1050 in transit to node 1052.

C. Overlapping Networks Topology

FIG. 12 illustrates an alternative embodiment of the fabric 1000 as afabric 1054 having an overlapping networks topology. The fabric 1054includes networks 1056 and 1058. As illustrated, each of the nodes 1062,1064, 1066, 1068, 1070, and 1072 may be connected to each of thenetworks. In other embodiments, the node 1072 may include an accesspoint for an Ethernet/WiFi network rather than an end point and may notbe present on either the network 1056 or network 1058, whichever is notthe Ethernet/WiFi network. Accordingly, a communication from node 1062to node 1068 may be passed through network 1056, network 1058, or somecombination thereof. In the illustrated embodiment, each node cancommunicate with any other node via any network using any networkdesired. Accordingly, unlike the star network topology of FIG. 11, theoverlapping networks topology may communicate directly between nodes viaany network without using inter-network routing.

D. Fabric Network Connection to Services

In addition to communications between devices within the home, a fabric(e.g., fabric 1000) may include services that may be located physicallynear other devices in the fabric or physically remote from such devices.The fabric connects to these services through one or more service endpoints. FIG. 13 illustrates an embodiment of a service 1074communicating with fabrics 1076, 1078, and 1080. The service 1074 mayinclude various services that may be used by devices in fabrics 1076,1078, and/or 1080. For example, in some embodiments, the service 1074may be a time of day service that supplies a time of day to devices, aweather service to provide various weather data (e.g., outsidetemperature, sunset, wind information, weather forecast, etc.), an echoservice that “pings” each device, data management services, devicemanagement services, and/or other suitable services. As illustrated, theservice 1074 may include a server 1082 (e.g., web server) thatstores/accesses relevant data and passes the information through aservice end point 1084 to one or more end points 1086 in a fabric, suchas fabric 1076. Although the illustrated embodiment only includes threefabrics with a single server 1082, it should be appreciated that theservice 1074 may connect to any number of fabrics and may includeservers in addition to the server 1082 and/or connections to additionalservices.

In certain embodiments, the service 1074 may also connect to a consumerdevice 1088, such as a phone, tablet, and/or computer. The consumerdevice 1088 may be used to connect to the service 1074 via a fabric,such as fabric 1076, an Internet connection, and/or some other suitableconnection method. The consumer device 1088 may be used to access datafrom one or more end points (e.g., electronic devices) in a fabriceither directly through the fabric or via the service 1074. In otherwords, using the service 1074, the consumer device 1088 may be used toaccess/manage devices in a fabric remotely from the fabric.

E. Communication Between Devices in a Fabric

As discussed above, each electronic device or node may communicate withany other node in the fabric, either directly or indirectly dependingupon fabric topology and network connection types. Additionally, somedevices (e.g., remote devices) may communicate through a service tocommunicate with other devices in the fabric. FIG. 14 illustrates anembodiment of a communication 1090 between two devices 1092 and 1094.The communication 1090 may span one or more networks either directly orindirectly through additional devices and/or services, as describedabove. Additionally, the communication 1090 may occur over anappropriate communication protocol, such as IPv6, using one or moretransport protocols. For example, in some embodiments the communication1090 may include using the transmission control protocol (TCP) and/orthe user datagram protocol (UDP). In some embodiments, the device 1092may transmit a first signal 1096 to the device 1094 using aconnectionless protocol (e.g., UDP). In certain embodiments, the device1092 may communicate with the device 1094 using a connection-orientedprotocol (e.g., TCP). Although the illustrated communication 1090 isdepicted as a bi-directional connection, in some embodiments, thecommunication 1090 may be a uni-directional broadcast.

i. Unique Local Address

As discussed above, data transmitted within a fabric received by a nodemay be redirected or passed through the node to another node dependingon the desired target for the communication. In some embodiments, thetransmission of the data may be intended to be broadcast to all devices.In such embodiments, the data may be retransmitted without furtherprocessing to determine whether the data should be passed along toanother node. However, some data may be directed to a specific endpoint.To enable addressed messages to be transmitted to desired endpoints,nodes may be assigned identification information.

Each node may be assigned a set of link-local addresses (LLA), oneassigned to each network interface. These LLAs may be used tocommunicate with other nodes on the same network. Additionally, the LLAsmay be used for various communication procedures, such as IPv6 NeighborDiscovery Protocol. In addition to LLAs, each node may be assigned aunique local address (ULA). In some embodiments, this may be referred toas an Extended Unique Local Address (EULA) because it containsinformation regarding the fabric of devices as well as a preferrednetwork over which to reach a device through the fabric.

FIG. 15 illustrates an embodiment of a unique local address (ULA) 1098that may be used to address each node in the fabric. In certainembodiments, the ULA 1098 may be formatted as an IPv6 address formatcontaining 128 bits divided into a global ID 1100, a subnet ID 1102, andan interface ID 1104. The global ID 1100 includes 40 bits and the subnetID 1102 includes 16 bits. The global ID 1100 and subnet ID 1102 togetherform a fabric ID 1103 for the fabric.

The fabric ID 1103 is a unique 64-bit identifier used to identify afabric. The fabric ID 1103 may be generated at creation of theassociated fabric using a pseudo-random algorithm. For example, thepseudo-random algorithm may 1) obtain the current time of day in 64-bitNTP format, 2) obtain the interface ID 1104 for the device, 3)concatenate the time of day with the interface ID 1104 to create a key,4) compute and SHA-1 digest on the key resulting in 160 bits, 5) use theleast significant 40 bits as the global ID 1100, and 6) concatenate theULA and set the least significant bit to 1 to create the fabric ID 1103.In certain embodiments, once the fabric ID 1103 is created with thefabric, the fabric ID 1103 remains until the fabric is dissolved.

The global ID 1100 identifies the fabric to which the node belongs. Thesubnet ID 1102 identifies logical networks within the fabric. The subnetID F3 may be assigned monotonically starting at one with the addition ofeach new logical network to the fabric. For example, a WiFi network maybe identified with a hex value of 0x01, and a later connected 802.15.4network may be identified with a hex value of 0x02 continuing onincrementally upon the connection of each new network to the fabric.

Finally, the ULA 1098 includes an interface ID 1104 that includes 64bits. The interface ID 1104 may be assigned using a globally-unique64-bit identifier according to the IEEE EUI-64 standard. For example,devices with IEEE 802 network interfaces may derive the interface ID1104 using a burned-in MAC address for the devices “primary interface.”In some embodiments, the designation of which interface is the primaryinterface may be determined arbitrarily. In other embodiments, aninterface type (e.g., WiFi) may be deemed the primary interface, whenpresent. If the MAC address for the primary interface of a device is 48bits rather than 64-bit, the 48-bit MAC address may be converted to aEUI-64 value via encapsulation (e.g., organizationally unique identifierencapsulating). In consumer devices (e.g., phones or computers), theinterface ID 1104 may be assigned by the consumer devices' localoperating systems.

ii. Routing Transmissions Between Logical Networks

As discussed above in relation to a star network topology, inter-networkrouting may occur in communication between two devices across logicalnetworks. In some embodiments, inter-network routing is based on thesubnet ID 1102. Each inter-networking node (e.g., node 1034 of FIG. 11)may maintain a list of other routing nodes (e.g., node B14 of FIG. 11)on the hub network 1020 and their respective attached periphery networks(e.g., periphery network 1024 of FIG. 11). When a packet arrivesaddressed to a node other than the routing node itself, the destinationaddress (e.g., address for node 1052 of FIG. 11) is compared to the listof network prefixes and a routing node (e.g., node 1044) is selectedthat is attached to the desired network (e.g., periphery network 1024).The packet is then forwarded to the selected routing node. If multiplenodes (e.g., 1034 and 1036) are attached to the same periphery network,routing nodes are selected in an alternating fashion.

Additionally, inter-network routing nodes may regularly transmitNeighbor Discovery Protocol (NDP) router advertisement messages on thehub network to alert consumer devices to the existence of the hubnetwork and allow them to acquire the subnet prefix. The routeradvertisements may include one or more route information options toassist in routing information in the fabric. For example, these routeinformation options may inform consumer devices of the existence of theperiphery networks and how to route packets the periphery networks.

In addition to, or in place of route information options, routing nodesmay act as proxies to provide a connection between consumer devices anddevices in periphery networks, such as the process 1105 as illustratedin FIG. 16. As illustrated, the process 1105 includes each peripherynetwork device being assigned a virtual address on the hub network bycombining the subnet ID 1102 with the interface ID 1104 for the deviceon the periphery network (block 1106). To proxy using the virtualaddresses, routing nodes maintain a list of all periphery nodes in thefabric that are directly reachable via one of its interfaces (block1108). The routing nodes listen on the hub network for neighborsolicitation messages requesting the link address of a periphery nodeusing its virtual address (block 1110). Upon receiving such a message,the routing node attempts to assign the virtual address to its hubinterface after a period of time (block 1112). As part of theassignment, the routing node performs duplicate address detection so asto block proxying of the virtual address by more than one routing node.After the assignment, the routing node responds to the neighborsolicitation message and receives the packet (block 1114). Uponreceiving the packet, the routing node rewrites the destination addressto be the real address of the periphery node (block 1116) and forwardsthe message to the appropriate interface (block 1118).

iii. Consumer Devices Connecting to a Fabric

To join a fabric, a consumer device may discover an address of a nodealready in the fabric that the consumer device wants to join.Additionally, if the consumer device has been disconnected from a fabricfor an extended period of time may need to rediscover nodes on thenetwork if the fabric topology/layout has changed. To aid indiscovery/rediscovery, fabric devices on the hub network may publishDomain Name System-Service Discovery (DNS-SD) records via mDNS thatadvertise the presence of the fabric and provide addresses to theconsumer device

Data Transmitted in the Fabric

After creation of a fabric and address creation for the nodes, data maybe transmitted through the fabric. Data passed through the fabric may bearranged in a format common to all messages and/or common to specifictypes of conversations in the fabric. In some embodiments, the messageformat may enable one-to-one mapping to JavaScript Object Notation(JSON) using a TLV serialization format discussed below. Additionally,although the following data frames are described as including specificsizes, it should be noted that lengths of the data fields in the dataframes may be varied to other suitable bit-lengths.

A. Security

Along with data intended to be transferred, the fabric may transfer thedata with additional security measures such as encryption, messageintegrity checks, and digital signatures. In some embodiments, a levelof security supported for a device may vary according to physicalsecurity of the device and/or capabilities of the device. In certainembodiments, messages sent between nodes in the fabric may be encryptedusing the Advanced Encryption Standard (AES) block cipher operating incounter mode (AES-CTR) with a 128-bit key. As discussed below, eachmessage contains a 32-bit message id. The message id may be combinedwith a sending nodes id to form a nonce for the AES-CTR algorithm. The32-bit counter enables 4 billion messages to be encrypted and sent byeach node before a new key is negotiated.

In some embodiments, the fabric may insure message integrity using amessage authentication code, such as HMAC-SHA-1, that may be included ineach encrypted message. In some embodiments, the message authenticationcode may be generated using a 160-bit message integrity key that ispaired one-to-one with the encryption key. Additionally, each node maycheck the message id of incoming messages against a list of recentlyreceived ids maintained on a node-by-node basis to block replay of themessages.

B. Tag Length Value (TLV) Formatting

To reduce power consumption, it is desirable to send at least a portionof the data sent over the fabric that compactly while enabling the datacontainers to flexibly represents data that accommodates skipping datathat is not recognized or understood by skipping to the next location ofdata that is understood within a serialization of the data. In certainembodiments, tag-length-value (TLV) formatting may be used to compactlyand flexibly encode/decode data. By storing at least a portion of thetransmitted data in TLV, the data may be compactly and flexiblystored/sent along with low encode/decode and memory overhead, asdiscussed below in reference to Table 7. In certain embodiments, TLV maybe used for some data as flexible, extensible data, but other portionsof data that is not extensible may be stored and sent in a understoodstandard protocol data unit (PDU).

Data formatted in a TLV format may be encoded as TLV elements of varioustypes, such as primitive types and container types. Primitive typesinclude data values in certain formats, such as integers or strings. Forexample, the TLV format may encode: 1, 2, 3, 4, or 8 bytesigned/unsigned integers, UTF-8 strings, byte strings,single/double-precision floating numbers (e.g., IEEE 754-1985 format),boolean, null, and other suitable data format types. Container typesinclude collections of elements that are then sub-classified ascontainer or primitive types. Container types may be classified intovarious categories, such as dictionaries, arrays, paths or othersuitable types for grouping TLV elements, known as members. A dictionaryis a collection of members each having distinct definitions and uniquetags within the dictionary. An array is an ordered collection of memberswith implied definitions or no distinct definitions. A path is anordered collection of members that described how to traverse a tree ofTLV elements.

As illustrated in FIG. 11, an embodiment of a TLV packet 1120 includesthree data fields: a tag field 1122, a length field 1124, and a valuefield 1126. Although the illustrated fields 1122, 1124, and 1126 areillustrated as approximately equivalent in size, the size of each fieldmay be variable and vary in size in relation to each other. In otherembodiments, the TLV packet 1120 may further include a control bytebefore the tag field 1122.

In embodiments having the control byte, the control byte may besub-divided into an element type field and a tag control field. In someembodiments, the element type field includes 5 lower bits of the controlbyte and the tag control field occupies the upper 3 bits. The elementtype field indicates the TLV element's type as well as the how thelength field 1124 and value field 1126 are encoded. In certainembodiments, the element type field also encodes Boolean values and/ornull values for the TLV. For example, an embodiment of an enumeration ofelement type field is provided in Table 1 below.

TABLE 1 Example element type field values. 7 6 5 4 3 2 1 0 0 0 0 0 0Signed Integer, 1 byte value value 0 0 0 0 1 Signed Integer, 2 bytevalue 0 0 0 1 0 Signed Integer, 4 byte value 0 0 0 1 1 Signed Integer, 8byte value 0 0 1 0 0 Unsigned Integer, 1 byte value 0 0 1 0 1 UnsignedInteger, 2 byte value 0 0 1 1 0 Unsigned Integer, 4 byte value 0 0 1 1 1Unsigned Integer, 8 byte value 0 1 0 0 0 Boolean False 0 1 0 0 1 BooleanTrue 0 1 0 1 0 Floating Point Number, 4 byte value 0 1 0 1 1 FloatingPoint Number, 8 byte value 0 1 1 0 0 UTF8-String, 1 byte length 0 1 1 01 UTF8-String, 2 byte length 0 1 1 1 0 UTF8-String, 4 byte length 0 1 11 1 UTF8-String, 8 byte length 1 0 0 0 0 Byte String, 1 byte length 1 00 0 1 Byte String, 2 byte length 1 0 0 1 0 Byte String, 4 byte length 10 0 1 1 Byte String, 8 byte length 1 0 1 0 0 Null 1 0 1 0 1 Dictionary 10 1 1 0 Array 1 0 1 1 1 Path 1 1 0 0 0 End of ContainerThe tag control field indicates a form of the tag in the tag field 1122assigned to the TLV element (including a zero-length tag). Examples, oftag control field values are provided in Table 2 below.

TABLE 2 Example values for tag control field. 7 6 5 4 3 2 1 0 0 0 0Anonymous, 0 bytes 0 0 1 Context-specific Tag, 1 byte 0 1 0 Core ProfileTag, 2 bytes 0 1 1 Core Profile Tag, 4 bytes 1 0 0 Implicit Profile Tag,2 bytes 1 0 1 Implicit Profile Tag, 4 bytes 1 1 0 Fully-qualified Tag, 6bytes 1 1 1 Fully-qualified Tag, 8 bytesIn other words, in embodiments having a control byte, the control bytemay indicate a length of the tag.

In certain embodiments, the tag field 1122 may include zero to eightbytes, such as eight, sixteen, thirty two, or sixty four bits. In someembodiments, the tag of the tag field may be classified asprofile-specific tags or context-specific tags. Profile-specific tagsidentify elements globally using a vendor Id, a profile Id, and/or tagnumber as discussed below. Context-specific tags identify TLV elementswithin a context of a containing dictionary element and may include asingle-byte tag number. Since context-specific tags are defined incontext of their containers, a single context-specific tag may havedifferent interpretations when included in different containers. In someembodiments, the context may also be derived from nested containers.

In embodiments having the control byte, the tag length is encoded in thetag control field and the tag field 1122 includes a possible threefields: a vendor Id field, a profile Id field, and a tag number field.In the fully-qualified form, the encoded tag field 1122 includes allthree fields with the tag number field including 16 or 32 bitsdetermined by the tag control field. In the implicit form, the tagincludes only the tag number, and the vendor Id and profile number areinferred from the protocol context of the TLV element. The core profileform includes profile-specific tags, as discussed above.Context-specific tags are encoded as a single byte conveying the tagnumber. Anonymous elements have zero-length tag fields 1122.

In some embodiments without a control byte, two bits may indicate alength of the tag field 1122, two bits may indicate a length of thelength field 1124, and four bits may indicate a type of informationstored in the value field 1126. An example of possible encoding for theupper 8 bits for the tag field is illustrated below in Table 3.

TABLE 3 Tag field of a TLV packet Byte 0 7 6 5 4 3 2 1 0 Description 0 0— — — — — —  Tag is 8 bits 0 1 — — — — — — Tag is 16 bits 1 0 — — — — —— Tag is 32 bits 1 1 — — — — — — Tag is 64 bits — — 0 0 — — — —  Lengthis 8 bits — — 0 1 — — — — Length is 16 bits — — 1 0 — — — — Length is 32bits — — 1 1 — — — — Length is 64 bits — — 0 0 0 0 Boolean — — 0 0 0 1Fixed 8-bit Unsigned — — 0 0 1 0 Fixed 8-bit Signed — — 0 0 1 1 Fixed16-bit Unsigned — — 0 1 0 0 Fixed 16-bit Signed — — 0 1 0 1 Fixed 32-bitUnsigned — — 0 1 1 0 Fixed 32-bit Signed — — 0 1 1 1 Fixed 64-bitUnsigned — — 1 0 0 0 Fixed 64-bit Signed — — 1 0 0 1 32-bit FloatingPoint — — 1 0 1 0 64-bit Floating Point — — 1 0 1 1 UTF-8 String — — 1 10 0 Opaque Data — — 1 1 0 1 ContainerAs illustrated in Table 3, the upper 8 bits of the tag field 1122 may beused to encode information about the tag field 1122, length field 1124,and the value field 1126, such that the tag field 112 may be used todetermine length for the tag field 122 and the length fields 1124.Remaining bits in the tag field 1122 may be made available foruser-allocated and/or user-assigned tag values.

The length field 1124 may include eight, sixteen, thirty two, or sixtyfour bits as indicated by the tag field 1122 as illustrated in Table 3or the element field as illustrated in Table 2. Moreover, the lengthfield 1124 may include an unsigned integer that represents a length ofthe encoded in the value field 1126. In some embodiments, the length maybe selected by a device sending the TLV element. The value field 1126includes the payload data to be decoded, but interpretation of the valuefield 1126 may depend upon the tag length fields, and/or control byte.For example, a TLV packet without a control byte including an 8 bit tagis illustrated in Table 4 below for illustration.

TABLE 4 Example of a TLV packet including an 8-bit tag Tag Length ValueDescription 0x0d 0x24 0x09 0x04 0x42 95 00 00 74.5 0x09 0x04 0x42 98 6666 76.2 0x09 0x04 0x42 94 99 9a 74.3 0x09 0x04 0x42 98 99 9a 76.3 0x090x04 0x42 95 33 33 74.6 0x09 0x04 0x42 98 33 33 76.1As illustrated in Table 4, the first line indicates that the tag field1122 and the length field 1124 each have a length of 8 bits.Additionally, the tag field 1122 indicates that the tag type is for thefirst line is a container (e.g., the TLV packet). The tag field 1124 forlines two through six indicate that each entry in the TLV packet has atag field 1122 and length field 1124 consisting of 8 bits each.Additionally, the tag field 1124 indicates that each entry in the TLVpacket has a value field 1126 that includes a 32-bit floating point.Each entry in the value field 1126 corresponds to a floating number thatmay be decoded using the corresponding tag field 1122 and length field1124 information. As illustrated in this example, each entry in thevalue field 1126 corresponds to a temperature in Fahrenheit. As can beunderstood, by storing data in a TLV packet as described above, data maybe transferred compactly while remaining flexible for varying lengthsand information as may be used by different devices in the fabric.Moreover, in some embodiments, multi-byte integer fields may betransmitted in little-endian order or big-endian order.

By transmitting TLV packets in using an order protocol (e.g.,little-endian) that may be used by sending/receiving device formats(e.g., JSON), data transferred between nodes may be transmitted in theorder protocol used by at least one of the nodes (e.g., little endian).For example, if one or more nodes include ARM or ix86 processors,transmissions between the nodes may be transmitted using little-endianbyte ordering to reduce the use of byte reordering. By reducing theinclusion of byte reordering, the TLV format enable devices tocommunicate using less power than a transmission that uses bytereordering on both ends of the transmission. Furthermore, TLV formattingmay be specified to provide a one-to-one translation between other datastorage techniques, such as JSON+ Extensible Markup Language (XML). Asan example, the TLV format may be used to represent the following XMLProperty List:

<?xml version=“1.0” encoding=“UTF-8”?> <!DOCTYPE plist PUBLIC “-//AppleComputer//DTD PLIST 1.0//EN”“http://www.apple.com/DTDs/PropertyList-1.0.dtd”> <plist version=“1.0”><dict>  <key>OfflineMode</key>  <false/>  <key>Network</key>  <dict>  <key>IPv4</key>   <dict>    <key>Method</key>    <string>dhcp</string>  </dict>   <key>IPv6</key>   <dict>    <key>Method</key>   <string>auto</string>   </dict>  </dict>  <key>Technologies</key> <dict>   <key>wifi</key>   <dict>    <key>Enabled</key>    <true/>   <key>Devices</key>    <dict>     <key>wifi_18b4300008b027</key>    <dict>     <key>Enabled</key>     <true/>    </dict>   </dict>  <key>Services</key>   <array>   <string>wifi_18b4300008b027_3939382d33204    16c70696e652054657272616365</string>   </array>  </dict>  <key>802.15.4</key>  <dict>  <key>Enabled</key>   <true/>   <key>Devices</key>   <dict>   <key>802.15.4_18b43000000002fac4</key>    <dict>    <key>Enabled</key>     <true/>    </dict>   </dict>   <key>Services</key>    <array>    <string>802.15.4_18b43000000002fac4_3    939382d3320416c70696e6520546572</string>    </array>   </dict> </dict>  <key>Services</key>  <dict> <key>wifi_18b4300008b027_3939382d3320416c70696e6520546572 72616365</key>   <dict>    <key>Name</key>    <string>998-3 AlpineTerrace</string>    <key>SSID</key>   <data>3939382d3320416c70696e652054657272616365    </data>   <key>Frequency</key>    <integer>2462</integer>   <key>AutoConnect</key>    <true/>    <key>Favorite</key>    <true/>   <key>Error</key>    <string/>    <key>Network</key>    <dict>    <key>IPv4</key>     <dict>      <key>DHCP</key>      <dict>      <key>LastAddress</key>       <data>0a02001e</data>      </dict>    </dict>     <key>IPv6</key>     <dict/>    </dict>   </dict>  <key>802.15.4_18b43000000002fac4_3939382d3320416c70696e  6520546572</key>   <dict>    <key>Name</key>    <string>998-3 AlpineTer</string>    <key>EPANID</key>   <data>3939382d3320416c70696e6520546572</data>    <key>Frequency</key>   <integer>2412</integer>    <key>AutoConnect</key>    <true/>   <key>Favorite</key>    <true/>    <key>Error</key>    <string/>   <key>Network</key>    <dict/>   </dict>  </dict> </dict> </plistAs an example, the above property list may be represented in tags of theabove described TLV format (without a control byte) according to Table 5below.

TABLE 5 Example representation of the XML Property List in TLV formatXML Key Tag Type Tag Number OfflineMode Boolean 1 IPv4 Container 3 IPv6Container 4 Method String 5 Technologies Container 6 WiFi Container 7802.15.4 Container 8 Enabled Boolean 9 Devices Container 10 ID String 11Services Container 12 Name String 13 SSID Data 14 EPANID Data 15Frequency 16-bit Unsigned 16 AutoConnect Boolean 17 Favorite Boolean 18Error String 19 DHCP String 20 LastAddress Data 21 Device Container 22Service Container 23Similarly, Table 6 illustrates an example of literal tag, length, andvalue representations for the example XML Property List.

TABLE 6 Example of literal values for tag, length, and value fields forXML Property List Tag Length Value Description 0x40 01 0x01 0OfflineMode 0x4d 02 0x14 Network 0x4d 03 0x07 Network.IPv4 0x4b 05 0x04“dhcp” Network.IPv4.Method 0x4d 04 0x07 Network.IPv6 0x4b 05 0x04 “auto”Network.IPv6.Method 0x4d 06 0xd6 Technologies 0x4d 07 0x65Technologies.wifi 0x40 09 0x01 1 Technologies.wifi.Enabled 0x4d 0a 0x5eTechnologies.wifi.Devices 0x4d 16 0x5bTechnologies.wifi.Devices.Device.[0] 0x4b 0b 0x13 “wifi_18b43 . . . ”Technologies.wifi.Devices.Device.[0].ID 0x40 09 0x01 1Technologies.wifi.Devices.Device.[0].Enabled 0x4d 0c 0x3eTechnologies.wifi.Devices.Device.[0].Services 0x0b 0x 3c “wifi_18b43 . .. ” Technologies.wifi.Devices.Device.[0].Services.[0] 0x4d 08 0x6bTechnologies.802.15.4 0x40 09 0x01 1 Technologies.802.15.4.Enabled 0x4d0a 0x64 Technologies.802.15.4.Devices 0x4d 16 0x61Technologies.802.15.4.Devices.Device.[0] 0x4b 0b 0x1a “802.15.4_18 . . .” Technologies.802.15.4.Devices.Device.[0].ID 0x40 09 0x01 1Technologies.802.15.4.Devices.Device.[0].Enabled 0x4d 0c 0x3dTechnologies.802.15.4.Devices.Device.[0].Services 0x0b 0x 3b“802.15.4_18 . . . ”Technologies.802.15.4.Devices.Device.[0].Services.[0] 0x4d 0c 0xcbServices 0x4d 17 0x75 Services.Service.[0] 0x4b 0b 0x13 “wifi_18b43 . .. ” Services.Service.[0].ID 0x4b 0d 0x14 “998-3 Alp . . . ”Services.Service.[0].Name 0x4c 0f 0x28 3939382d . . .Services.Service.[0].SSID 0x45 10 0x02 2462Services.Service.[0].Frequency 0x40 11 0x01 1Services.Service.[0].AutoConnect 0x40 12 0x01 1Services.Service.[0].Favorite 0x4d 02 0x0d Services.Service.[0].Network0x4d 03 0x0a Services.Service.[0].Network.IPv4 0x4d 14 0x07Services.Service.[0].Network.IPv4.DHCP 0x45 15 0x04 0x0a02001eServices.Service.[0].Network.IPv4.LastAddress 0x4d 17 0x50Services.Service.[1] 0x4b 0b 0x1a “802.15.4_18 . . . ”Services.Service.[1].ID 0x4c 0d 0x10 “998-3 Alp . . . ”Services.Service.[1].Name 0x4c 0f 0x10 3939382d . . .Services.Service.[1].EPANID 0x45 10 0x02 2412Services.Service.[1].Frequency 0x40 11 0x01 1Services.Service.[1].AutoConnect 0x40 12 0x01 1Services.Service.[1].FavoriteThe TLV format enables reference of properties that may also beenumerated with XML, but does so with a smaller storage size. Forexample, Table 7 illustrates a comparison of data sizes of the XMLProperty List, a corresponding binary property list, and the TLV format.

TABLE 7 Comparison of the sizes of property list data sizes. List TypeSize in Bytes Percentage of XML Size XML 2,199 — Binary 730 −66.8% TLV450 −79.5%

By reducing the amount of data used to transfer data, the TLV formatenables the fabric 1000 transfer data to and/or from devices havingshort duty cycles due to limited power (e.g., battery supplied devices).In other words, the TLV format allows flexibility of transmission whileincreasing compactness of the data to be transmitted.

C. General Message Protocol

In addition to sending particular entries of varying sizes, data may betransmitted within the fabric using a general message protocol that mayincorporate TLV formatting. An embodiment of a general message protocol(GMP) 1128 is illustrated in FIG. 18. In certain embodiments, thegeneral message protocol (GMP) 1128 may be used to transmit data withinthe fabric. The GMP 1128 may be used to transmit data via connectionlessprotocols (e.g., UDP) and/or connection-oriented protocols (e.g., TCP).Accordingly, the GMP 1128 may flexibly accommodate information that isused in one protocol while ignoring such information when using anotherprotocol. Moreover, the GMP 1226 may enable omission of fields that arenot used in a specific transmission. Data that may be omitted from oneor more GMP 1226 transfers is generally indicated using grey bordersaround the data units. In some embodiments, the multi-byte integerfields may be transmitted in a little-endian order or a big-endianorder.

i. Packet Length

In some embodiments, the GMP 1128 may include a Packet Length field1130. In some embodiments, the Packet Length field 1130 includes 2bytes. A value in the Packet Length field 1130 corresponds to anunsigned integer indicating an overall length of the message in bytes,excluding the Packet Length field 1130 itself. The Packet Length field1130 may be present when the GMP 1128 is transmitted over a TCPconnection, but when the GMP 1128 is transmitted over a UDP connection,the message length may be equal to the payload length of the underlyingUDP packet obviating the Packet Length field 1130.

ii. Message Header

The GMP 1128 may also includes a Message Header 1132 regardless ofwhether the GMP 1128 is transmitted using TCP or UDP connections. Insome embodiments, the Message Header 1132 includes two bytes of dataarranged in the format illustrated in FIG. 19. As illustrated in FIG.19, the Message Header 1132 includes a Version field 1156. The Versionfield 1156 corresponds to a version of the GMP 1128 that is used toencode the message. Accordingly, as the GMP 1128 is updated, newversions of the GMP 1128 may be created, but each device in a fabric maybe able to receive a data packet in any version of GMP 1128 known to thedevice. In addition to the Version field 1156, the Message Header 1132may include an S Flag field 1158 and a D Flag 1160. The S Flag 1158 is asingle bit that indicates whether a Source Node Id (discussed below)field is included in the transmitted packet. Similarly, the D Flag 1160is a single bit that indicates whether a Destination Node Id (discussedbelow) field is included in the transmitted packet.

The Message Header 1132 also includes an Encryption Type field 1162. TheEncryption Type field 1162 includes four bits that specify which type ofencryption/integrity checking applied to the message, if any. Forexample, 0x0 may indicate that no encryption or message integritychecking is included, but a decimal 0x1 may indicate that AES-128-CTRencryption with HMAC-SHA-1 message integrity checking is included.

Finally, the Message Header 1132 further includes a Signature Type field1164. The Signature Type field 1164 includes four bits that specifywhich type of digital signature is applied to the message, if any. Forexample, 0x0 may indicate that no digital signature is included in themessage, but 0x1 may indicate that the Elliptical Curve DigitalSignature Algorithm (ECDSA) with Prime256v1 elliptical curve parametersis included in the message.

iii. Message Id

Returning to FIG. 18, the GMP 1128 also includes a Message Id field 1134that may be included in a transmitted message regardless of whether themessage is sent using TCP or UDP. The Message Id field 1134 includesfour bytes that correspond to an unsigned integer value that uniquelyidentifies the message from the perspective of the sending node. In someembodiments, nodes may assign increasing Message Id 1134 values to eachmessage that they send returning to zero after reaching 2³² messages.

iv. Source Node Id

In certain embodiments, the GMP 1128 may also include a Source Node Idfield 1136 that includes eight bytes. As discussed above, the SourceNode Id field 1136 may be present in a message when the single-bit SFlag 1158 in the Message Header 1132 is set to 1. In some embodiments,the Source Node Id field 1136 may contain the Interface ID 1104 of theULA 1098 or the entire ULA 1098. In some embodiments, the bytes of theSource Node Id field 1136 are transmitted in an ascending index-valueorder (e.g., EUI[0] then EUI[1] then EUI[2] then EUI[3], etc.).

v. Destination Node Id

The GMP 1128 may include a Destination Node Id field 1138 that includeseight bytes. The Destination Node Id field 1138 is similar to the SourceNode Id field 1136, but the Destination Node Id field 1138 correspondsto a destination node for the message. The Destination Node Id field1138 may be present in a message when the single-bit D Flag 1160 in theMessage Header 1132 is set to 1. Also similar to the Source Node Idfield 1136, in some embodiments, bytes of the Destination Node Id field1138 may be transmitted in an ascending index-value order (e.g., EUI[0]then EUI[1] then EUI[2] then EUI[3], etc.).

vi. Key Id

In some embodiments, the GMP 1128 may include a Key Id field 1140. Incertain embodiments, the Key Id field 1140 includes two bytes. The KeyId field 1140 includes an unsigned integer value that identifies theencryption/message integrity keys used to encrypt the message. Thepresence of the Key Id field 1140 may be determined by the value ofEncryption Type field 1162 of the Message Header 1132. For example, insome embodiments, when the value for the Encryption Type field 1162 ofthe Message Header 1132 is 0x0, the Key Id field 1140 may be omittedfrom the message.

An embodiment of the Key Id field 1140 is presented in FIG. 20. In theillustrated embodiment, the Key Id field 1140 includes a Key Type field1166 and a Key Number field 1168. In some embodiments, the Key Typefield 1166 includes four bits. The Key Type field 1166 corresponds to anunsigned integer value that identifies a type of encryption/messageintegrity used to encrypt the message. For example, in some embodiments,if the Key Type field 1166 is 0x0, the fabric key is shared by all ormost of the nodes in the fabric. However, if the Key Type field 1166 is0x1, the fabric key is shared by a pair of nodes in the fabric.

The Key Id field 1140 also includes a Key Number field 1168 thatincludes twelve bits that correspond to an unsigned integer value thatidentifies a particular key used to encrypt the message out of a set ofavailable keys, either shared or fabric keys.

vii. Payload Length

In some embodiments, the GMP 1128 may include a Payload Length field1142. The Payload Length field 1142, when present, may include twobytes. The Payload Length field 1142 corresponds to an unsigned integervalue that indicates a size in bytes of the Application Payload field.The Payload Length field 1142 may be present when the message isencrypted using an algorithm that uses message padding, as describedbelow in relation to the Padding field.

viii. Initialization Vector

In some embodiments, the GMP 1128 may also include an InitializationVector (IV) field 1144. The IV field 1144, when present, includes avariable number of bytes of data. The IV field 1144 containscryptographic IV values used to encrypt the message. The IV field 1144may be used when the message is encrypted with an algorithm that uses anIV. The length of the IV field 1144 may be derived by the type ofencryption used to encrypt the message.

ix. Application Payload

The GMP 1128 includes an Application Payload field 1146. The ApplicationPayload field 1146 includes a variable number of bytes. The ApplicationPayload field 1146 includes application data conveyed in the message.The length of the Application Payload field 1146 may be determined fromthe Payload Length field 1142, when present. If the Payload Length field1142 is not present, the length of the Application Payload field 1146may be determined by subtracting the length of all other fields from theoverall length of the message and/or data values included within theApplication Payload 1146 (e.g., TLV).

An embodiment of the Application Payload field 1146 is illustrated inFIG. 21. The Application Payload field 1146 includes an APVersion field1170. In some embodiments, the APVersion field 1170 includes eight bitsthat indicate what version of fabric software is supported by thesending device. The Application Payload field 1146 also includes aMessage Type field 1172. The Message Type field 1172 may include eightbits that correspond to a message operation code that indicates the typeof message being sent within a profile. For example, in a softwareupdate profile, a 0x00 may indicate that the message being sent is animage announce. The Application Payload field 1146 further includes anExchange Id field 1174 that includes sixteen bits that corresponds to anexchange identifier that is unique to the sending node for thetransaction.

In addition, the Application Payload field 1146 includes a Profile Idfield 1176. The Profile Id 1176 indicates a “theme of discussion” usedto indicate what type of communication occurs in the message. TheProfile Id 1176 may correspond to one or more profiles that a device maybe capable of communicating. For example, the Profile Id 1176 mayindicate that the message relates to a core profile, a software updateprofile, a status update profile, a data management profile, a climateand comfort profile, a security profile, a safety profile, and/or othersuitable profile types. Each device on the fabric may include a list ofprofiles which are relevant to the device and in which the device iscapable of “participating in the discussion.” For example, many devicesin a fabric may include the core profile, the software update profile,the status update profile, and the data management profile, but onlysome devices would include the climate and comfort profile. TheAPVersion field 1170, Message Type field 1172, the Exchange Id field,the Profile Id field 1176, and the Profile-Specific Header field 1176,if present, may be referred to in combination as the “ApplicationHeader.”

In some embodiments, an indication of the Profile Id via the Profile Idfield 1176 may provide sufficient information to provide a schema fordata transmitted for the profile. However, in some embodiments,additional information may be used to determine further guidance fordecoding the Application Payload field 1146. In such embodiments, theApplication Payload field 1146 may include a Profile-Specific Headerfield 1178. Some profiles may not use the Profile-Specific Header field1178 thereby enabling the Application Payload field 1146 to omit theProfile-Specific Header field 1178. Upon determination of a schema fromthe Profile Id field 1176 and/or the Profile-Specific Header field 1178,data may be encoded/decoded in the Application Payload sub-field 1180.The Application Payload sub-field 1180 includes the core applicationdata to be transmitted between devices and/or services to be stored,rebroadcast, and/or acted upon by the receiving device/service.

x. Message Integrity Check

Returning to FIG. 18, in some embodiments, the GMP 1128 may also includea Message Integrity Check (MIC) field 1148. The MIC field 1148, whenpresent, includes a variable length of bytes of data containing a MICfor the message. The length and byte order of the field depends upon theintegrity check algorithm in use. For example, if the message is checkedfor message integrity using HMAC-SHA-1, the MIC field 1148 includestwenty bytes in big-endian order. Furthermore, the presence of the MICfield 1148 may be determined by whether the Encryption Type field 1162of the Message Header 1132 includes any value other than 0x0.

xi. Padding

The GMP 1128 may also include a Padding field 1150. The Padding field1150, when present, includes a sequence of bytes representing acryptographic padding added to the message to make the encrypted portionof the message evenly divisible by the encryption block size. Thepresence of the Padding field 1150 may be determined by whether the typeof encryption algorithm (e.g., block ciphers in cipher-block chainingmode) indicated by the Encryption Type field 1162 in the Message Header1132 uses cryptographic padding.

xii. Encryption

The Application Payload field 1146, the MIC field 1148, and the Paddingfield 1150 together form an Encryption block 1152. The Encryption block1152 includes the portions of the message that are encrypted when theEncryption Type field 1162 in the Message Header 1132 is any value otherthan 0x0.

xiii. Message Signature

The GMP 1128 may also include a Message Signature field 1154. TheMessage Signature field 1154, when present, includes a sequence of bytesof variable length that contains a cryptographic signature of themessage. The length and the contents of the Message Signature field maybe determined according to the type of signature algorithm in use andindicated by the Signature Type field 1164 of the Message Header 1132.For example, if ECDSA using the Prime256v1 elliptical curve parametersis the algorithm in use, the Message Signature field 1154 may includetwo thirty-two bit integers encoded in little-endian order.

Profiles and Protocols

As discussed above, one or more schemas of information may be selectedupon desired general discussion type for the message. A profile mayconsist of one or more schemas. For example, one set of schemas ofinformation may be used to encode/decode data in the Application Payloadsub-field 1180 when one profile is indicated in the Profile Id field1176 of the Application Payload 1146. However, a different set ofschemas may be used to encode/decode data in the Application Payloadsub-field 1180 when a different profile is indicated in the Profile Idfield 1176 of the Application Payload 1146.

Additionally, in certain embodiments, each device may include a set ofmethods used to process profiles. For example, a core protocol mayinclude the following profiles: GetProfiles, GetSchema, GetSchemas,GetProperty, GetProperties, SetProperty, SetProperties, RemoveProperty,RemoveProperties, RequestEcho, NotifyPropertyChanged, and/orNotifyPropertiesChanged. The Get Profiles method may return an array ofprofiles supported by a queried node. The GetSchema and GetSchemasmethods may respectively return one or all schemas for a specificprofile. GetProperty and GetProperties may respectively return a valueor all value pairs for a profile schema. SetProperty and SetPropertiesmay respectively set single or multiple values for a profile schema.RemoveProperty and RemoveProperties may respectively attempt to remove asingle or multiple values from a profile schema. RequestEcho may send anarbitrary data payload to a specified node which the node returnsunmodified. NotifyPropertyChange and NotifyPropertiesChanged mayrespectively issue a notification if a single/multiple value pairs havechanged for a profile schema.

To aid in understanding profiles and schemas, a non-exclusive list ofprofiles and schemas are provided below for illustrative purposes.

A. Status Reporting

A status reporting schema is presented as the status reporting frame1182 in FIG. 22. The status reporting schema may be a separate profileor may be included in one or more profiles (e.g., a core profile). Incertain embodiments, the status reporting frame 1182 includes a profilefield 1184, a status code field 1186, a next status field 1188, and mayinclude an additional status info field 1190.

i. Profile Field

In some embodiments, the profile field 1184 includes four bytes of datathat defines the profile under which the information in the presentstatus report is to be interpreted. An embodiment of the profile field1184 is illustrated in FIG. 23 with two sub-fields. In the illustratedembodiment, the profile field 1184 includes a profile Id sub-field 1192that includes sixteen bits that corresponds to a vendor-specificidentifier for the profile under which the value of the status codefield 1186 is defined. The profile field 1184 may also includes a vendorId sub-field 1194 that includes sixteen bits that identifies a vendorproviding the profile identified in the profile Id sub-field 1192.

ii. Status Code

In certain embodiments, the status code field 1186 includes sixteen bitsthat encode the status that is being reported. The values in the statuscode field 1186 are interpreted in relation to values encoded in thevendor Id sub-field 1192 and the profile Id sub-field 1194 provided inthe profile field 1184. Additionally, in some embodiments, the statuscode space may be divided into four groups, as indicated in Table 8below.

TABLE 8 Status Code Range Table Range Name Description 0x0000 . . .0x0010 success A request was successfully processed. 0x0011 . . . 0x0020client error An error has or may have occurred on the client-side of aclient/server exchange. For example, the client has made a badly-formedrequest. 0x0021 . . . 0x0030 server error An error has or may haveoccurred on the server side of a client/server exchange. For example,the server has failed to process a client request to an operating systemerror. 0x0031 . . . 0x0040 continue/redirect Additional processing willbe used, such as redirection, to complete a particular exchange, but noerrors yet.Although Table 8 identifies general status code ranges that may be usedseparately assigned and used for each specific profile Id, in someembodiments, some status codes may be common to each of the profiles.For example, these profiles may be identified using a common profile(e.g., core profile) identifier, such as 0x00000000.

iii. Next Status

In some embodiments, the next status code field 1188 includes eightbits. The next status code field 1188 indicates whether there isfollowing status information after the currently reported status. Iffollowing status information is to be included, the next status codefield 1188 indicates what type of status information is to be included.In some embodiments, the next status code field 1188 may always beincluded, thereby potentially increasing the size of the message.However, by providing an opportunity to chain status informationtogether, the potential for overall reduction of data sent may bereduced. If the next status field 1186 is 0x00, no following statusinformation field 1190 is included. However, non-zero values mayindicate that data may be included and indicate the form in which thedata is included (e.g., in a TLV packet).

iv. Additional Status Info

When the next status code field 1188 is non-zero, the additional statusinfo field 1190 is included in the message. If present, the status itemfield may contain status in a form that may be determined by the valueof the preceding status type field (e.g., TLV format)

B. Software Update

The software update profile or protocol is a set of schemas and aclient/server protocol that enables clients to be made aware of or seekinformation about the presence of software that they may download andinstall. Using the software update protocol, a software image may beprovided to the profile client in a format known to the client. Thesubsequent processing of the software image may be generic,device-specific, or vendor-specific and determined by the softwareupdate protocol and the devices.

i. General Application Headers for the Application Payload

In order to be recognized and handled properly, software update profileframes may be identified within the Application Payload field 1146 ofthe GMP 1128. In some embodiments, all software update profile framesmay use a common Profile Id 1176, such as 0x0000000C. Additionally,software update profile frames may include a Message Type field 1172that indicates additional information and may chosen according to Table9 below and the type of message being sent.

TABLE 9 Software update profile message types Type Message 0x00 imageannounce 0x01 image query 0x02 image query response 0x03 download notify0x04 notify response 0x05 update notify 0x06 . . . 0xff reservedAdditionally, as described below, the software update sequence may beinitiated by a server sending the update as an image announce or aclient receiving the update as an image query. In either embodiment, anExchange Id 1174 from the initiating event is used for all messages usedin relation to the software update.

ii. Protocol Sequence

FIG. 24 illustrates an embodiment of a protocol sequence 1196 for asoftware update between a software update client 1198 and a softwareupdate server 1200. In certain embodiments, any device in the fabric maybe the software update client 1198 or the software update server 1200.Certain embodiments of the protocol sequence 1196 may include additionalsteps, such as those illustrated as dashed lines, that may be omitted insome software update transmissions.

1. Service Discovery

In some embodiments, the protocol sequence 1196 begins with a softwareupdate profile server announcing a presence of the update. However, inother embodiments, such as the illustrated embodiment, the protocolsequence 1196 begins with a service discovery 1202, as discussed above.

2. Image Announce

In some embodiments, an image announce message 1204 may be multicast orunicast by the software update server 1200. The image announce message1204 informs devices in the fabric that the server 1200 has a softwareupdate to offer. If the update is applicable to the client 1198, uponreceipt of the image announce message 1204, the software update client1198 responds with an image query message 1206. In certain embodiments,the image announce message 1204 may not be included in the protocolsequence 1196. Instead, in such embodiments, the software update client1198 may use a polling schedule to determine when to send the imagequery message 1206.

3. Image Query

In certain embodiments, the image query message 1206 may be unicast fromthe software update client 1198 either in response to an image announcemessage 1204 or according to a polling schedule, as discussed above. Theimage query message 1206 includes information from the client 1198 aboutitself. An embodiment of a frame of the image query message 1206 isillustrated in FIG. 25. As illustrated in FIG. 25, certain embodimentsof the image query message 1206 may include a frame control field 1218,a product specification field 1220, a vendor specific data field 1222, aversion specification field 1224, a locale specification field 1226, anintegrity type supported field 1228, and an update schemes supportedfield 1230.

a. Frame Control

The frame control field 1218 includes 1 byte and indicates variousinformation about the image query message 1204. An example of the framecontrol field 128 is illustrated in FIG. 26. As illustrated, the framecontrol field 1218 may include three sub-fields: vendor specific flag1232, locale specification flag 1234, and a reserved field S3. Thevendor specific flag 1232 indicates whether the vendor specific datafield 1222 is included in the message image query message. For example,when the vendor specific flag 1232 is 0 no vendor specific data field1222 may be present in the image query message, but when the vendorspecific flag 1232 is 1 the vendor specific data field 1222 may bepresent in the image query message. Similarly, a 1 value in the localespecification flag 1234 indicates that a locale specification field 1226is present in the image query message, and a 0 value indicates that thelocale specification field 1226 in not present in the image querymessage.

b. Product Specification

The product specification field 1220 is a six byte field. An embodimentof the product specification field 1220 is illustrated in FIG. 27. Asillustrated, the product specification field 1220 may include threesub-fields: a vendor Id field 1236, a product Id field 1238, and aproduct revision field 1240. The vendor Id field 1236 includes sixteenbits that indicate a vendor for the software update client 1198. Theproduct Id field 1238 includes sixteen bits that indicate the deviceproduct that is sending the image query message 1206 as the softwareupdate client 1198. The product revision field 1240 includes sixteenbits that indicate a revision attribute of the software update client1198.

c. Vendor Specific Data

The vendor specific data field 1222, when present in the image querymessage 1206, has a length of a variable number of bytes. The presenceof the vendor specific data field 1222 may be determined from the vendorspecific flag 1232 of the frame control field 1218. When present, thevendor specific data field 1222 encodes vendor specific informationabout the software update client 1198 in a TLV format, as describedabove.

d. Version Specification

An embodiment of the version specification field 1224 is illustrated inFIG. 28. The version specification field 1224 includes a variable numberof bytes sub-divided into two sub-fields: a version length field 1242and a version string field 1244. The version length field 1242 includeseight bits that indicate a length of the version string field 1244. Theversion string field 1244 is variable in length and determined by theversion length field 1242. In some embodiments, the version string field1244 may be capped at 255 UTF-8 characters in length. The value encodedin the version string field 1244 indicates a software version attributefor the software update client 1198.

e. Locale Specification

In certain embodiments, the locale specification field 1226 may beincluded in the image query message 1206 when the locale specificationflag 1234 of the frame control 1218 is 1. An embodiment of the localespecification field 1226 is illustrated in FIG. 29. The illustratedembodiment of the locale specification field 1226 includes a variablenumber of bytes divided into two sub-fields: a locale string lengthfield 1246 and a locale string field 1248. The locale string lengthfield 1246 includes eight bits that indicate a length of the localestring field 1248. The locale string field 1248 of the localespecification field 1226 may be variable in length and contain a stringof UTF-8 characters encoding a local description based on PortableOperating System Interface (POSIX) locale codes. The standard format forPOSIX locale codes is [language[_territory][.codeset][@modifier]] Forexample, the POSIX representation for Australian English is en_AU.UTF8.

f. Integrity Types Supported

An embodiment of the integrity types field 1228 is illustrated in FIG.30. The integrity types supported field 1228 includes two to four bytesof data divided into two sub-fields: a type list length field 1250 andan integrity type list field 1252. The type list length field 1250includes eight bits that indicate the length in bytes of the integritytype list field 1252. The integrity type list field 1252 indicates thevalue of the software update integrity type attribute of the softwareupdate client 1198. In some embodiments, the integrity type may bederived from Table 10 below.

TABLE 10 Example integrity types Value Integrity Type 0x00 SHA-160 0x01SHA-256 0x02 SHA-512The integrity type list field 1252 may contain at least one element fromTable 10 or other additional values not included.

g. Update Schemes Supported

An embodiment of the schemes supported field 1230 is illustrated in FIG.31. The schemes supported field 1230 includes a variable number of bytesdivided into two sub-fields: a scheme list length field 1254 and anupdate scheme list field 1256. The scheme list length field 1254includes eight bits that indicate a length of the update scheme listfield in bytes. The update scheme list field 1256 of the update schemessupported field 1222 is variable in length determined by the scheme listlength field 1254. The update scheme list field 1256 represents anupdate schemes attributes of the software update profile of the softwareupdate client 1198. An embodiment of example values is shown in Table 11below.

TABLE 11 Example update schemes Value Update Scheme 0x00 HTTP 0x01 HTTPS0x02 SFTP 0x03 Fabric-specific File Transfer Protocol (e.g., Bulk DataTransfer discussed below)Upon receiving the image query message 1206, the software update server1200 uses the transmitted information to determine whether the softwareupdate server 1200 has an update for the software update client 1198 andhow best to deliver the update to the software update client 1198.

4. Image Query Response

Returning to FIG. 24, after the software update server 1200 receives theimage query message 1206 from the software update client 1198, thesoftware update server 1200 responds with an image query response 1208.The image query response 1208 includes either information detailing whyan update image is not available to the software update client 1198 orinformation about the available image update to enable to softwareupdate client 1198 to download and install the update.

An embodiment of a frame of the image query response 1208 is illustratedin FIG. 32. As illustrated, the image query response 1208 includes fivepossible sub-fields: a query status field 1258, a uniform resourceidentifier (URI) field 1260, an integrity specification field 1262, anupdate scheme field 1264, and an update options field 1266.

a. Query Status

The query status field 1258 includes a variable number of bytes andcontains status reporting formatted data, as discussed above inreference to status reporting. For example, the query status field 1258may include image query response status codes, such as those illustratedbelow in Table 12.

TABLE 12 Example image query response status codes Profile CodeDescription 0x00000000 0x0000 The server has processed the image querymes- sage 1206 and has an update for the software update client 1198.0x0000000C 0x0001 The server has processed the image query mes- sage1206, but the server does not have an update for the software updateclient 1198. 0x00000000 0x0010 The server could not process the requestbe- cause of improper form for the request. 0x00000000 0x0020 The servercould not process the request due to an internal error

b. URI

The URI field 1260 includes a variable number of bytes. The presence ofthe URI field 1260 may be determined by the query status field 1258. Ifthe query status field 1258 indicates that an update is available, theURI field 1260 may be included. An embodiment of the URI field 1260 isillustrated in FIG. 33. The URI field 1260 includes two sub-fields: aURI length field 1268 and a URI string field 1270. The URI length field1268 includes sixteen bits that indicates the length of the URI stringfield 1270 in UTF-8 characters. The URI string field 1270 and indicatesthe URI attribute of the software image update being presented, suchthat the software update client 1198 may be able to locate, download,and install a software image update, when present.

c. Integrity Specification

The integrity specification field 1262 may variable in length andpresent when the query status field 1258 indicates that an update isavailable from the software update server 1198 to the software updateclient 1198. An embodiment of the integrity specification field 1262 isillustrated in FIG. 34. As illustrated, the integrity specificationfield 1262 includes two sub-fields: an integrity type field 1272 and anintegrity value field 1274. The integrity type field 1272 includes eightbits that indicates an integrity type attribute for the software imageupdate and may be populated using a list similar to that illustrated inTable 10 above. The integrity value field 1274 includes the integrityvalue that is used to verify that the image update message hasmaintained integrity during the transmission.

d. Update Scheme

The update scheme field 1264 includes eight bits and is present when thequery status field 1258 indicates that an update is available from thesoftware update server 1198 to the software update client 1198. Ifpresent, the update scheme field 1264 indicates a scheme attribute forthe software update image being presented to the software update server1198.

e. Update Options

The update options field 1266 includes eight bits and is present whenthe query status field 1258 indicates that an update is available fromthe software update server 1198 to the software update client 1198. Theupdate options field 1266 may be sub-divided as illustrated in FIG. 35.As illustrated, the update options field 1266 includes four sub-fields:an update priority field 1276, an update condition field 1278, a reportstatus flag 1280, and a reserved field 1282. In some embodiments, theupdate priority field 1276 includes two bits. The update priority field1276 indicates a priority attribute of the update and may be determinedusing values such as those illustrated in Table 13 below.

TABLE 13 Example update priority values Value Description 00 Normal -update during a period of low network traffic 01 Critical - update asquickly as possibleThe update condition field 1278 includes three bits that may be used todetermine conditional factors to determine when or if to update. Forexample, values in the update condition field 1278 may be decoded usingthe Table 14 below.

TABLE 14 Example update conditions Value Decription 0 Update withoutconditions 1 Update if the version of the software running on the updateclient software does not match the update version. 2 Update if theversion of the software running on the update client software is olderthan the update version. 3 Update if the user opts into an update with auser interfaceThe report status flag 1280 is a single bit that indicates whether thesoftware update client 1198 should respond with a download notifymessage 1210. If the report status flag 1280 is set to 1 the softwareupdate server 1198 is requesting a download notify message 1210 to besent after the software update is downloaded by the software updateclient 1200.

If the image query response 1208 indicates that an update is available.The software update client 1198 downloads 1210 the update using theinformation included in the image query response 1208 at a timeindicated in the image query response 1208.

5. Download Notify

After the update download 1210 is successfully completed or failed andthe report status flag 1280 value is 1, the software update client 1198may respond with the download notify message 1212. The download notifymessage 1210 may be formatted in accordance with the status reportingformat discussed above. An example of status codes used in the downloadnotify message 1212 is illustrated in Table 15 below.

TABLE 15 Example download notify status codes Profile Code Description0x00000000 0x0000 The download has been completed, and integrityverified 0x0000000C 0x0020 The download could not be completed due tofaulty download instructions. 0x0000000C 0x0021 The image query responsemessage 1208 appears proper, but the download or integrity verificationfailed. 0x0000000C 0x0022 The integrity of the download could not beverified.In addition to the status reporting described above, the download notifymessage 1208 may include additional status information that may berelevant to the download and/or failure to download.

6. Notify Response

The software update server 1200 may respond with a notify responsemessage 1214 in response to the download notify message 1212 or anupdate notify message 1216. The notify response message 1214 may includethe status reporting format, as described above. For example, the notifyresponse message 1214 may include status codes as enumerated in Table 16below.

TABLE 16 Example notify response status codes Profile Code Description0x00000000 0x0030 Continue - the notification is acknowledged, but theupdate has not completed, such as download notify message 1214 receivedbut update notify message 1216 has not. 0x00000000 0x0000 Success- thenotification is acknowledged, and the update has completed. 0x0000000C0x0023 Abort - the notification is acknowledged, but the server cannotcontinue the update. 0x0000000C 0x0031 Retry query - the notification isacknowledged, and the software update client 1198 is directed to retrythe update by submitting another image query message 1206.In addition to the status reporting described above, the notify responsemessage 1214 may include additional status information that may berelevant to the download, update, and/or failure to download/update thesoftware update.

7. Update Notify

After the update is successfully completed or failed and the reportstatus flag 1280 value is 1, the software update client 1198 may respondwith the update notify message 1216. The update notify message 1216 mayuse the status reporting format described above. For example, the updatenotify message 1216 may include status codes as enumerated in Table 17below.

TABLE 17 Example update notify status codes Profile Code Description0x00000000 0x0000 Success - the update has been completed. 0x0000000C0x0010 Client error - the update failed due to a problem in the softwareupdate client 1198.In addition to the status reporting described above, the update notifymessage 1216 may include additional status information that may berelevant to the update and/or failure to update.

C. Data Management Protocol

Data management may be included in a common profile (e.g., core profile)used in various electronic devices within the fabric or may bedesignated as a separate profile. In either situation, the devicemanagement protocol (DMP) may be used for nodes to browse, share, and/orupdate node-resident information. A sequence 1284 used in the DMP isillustrated in FIG. 36. The sequence 1284 illustrates a viewing node1286 that requests to view and/or change resident data of a viewed node1288. Additionally, the viewing node 1286 may request to view theresident data using one of several viewing options, such as a snapshotrequest, a watching request that the viewing persists over a period oftime, or other suitable viewing type. Each message follows the formatfor the Application Payload 1146 described in reference to FIG. 21. Forexample, each message contains a profile Id 1176 that corresponds to thedata management profile and/or the relevant core profile, such as0x235A0000. Each message also contains a message type 1172. The messagetype 1172 may be used to determine various factors relating theconversation, such as viewing type for the view. For example, in someembodiments, the message type field 1172 may be encoded/decodedaccording to Table 18 below.

TABLE 18 Example software update profile message types Type Message 0x00snapshot request 0x01 watch request 0x02 periodic update request 0x03refresh update 0x04 cancel view update 0x05 view response 0x06 explicitupdate request 0x07 view update request 0x08 update response

i. View Request

Although a view request message 1290 requests to view node-residentdata, the type of request may be determined by the message type field1172, as discussed above. Accordingly each request type may include adifferent view request frame.

1. Snapshot Request

A snapshot request may be sent by the viewing node 1286 when the viewingnode 1286 desires an instantaneous view into the node-resident data onthe viewed node 1288 without requesting future updates. An embodiment ofa snapshot request frame 1292 is illustrated in FIG. 37.

As illustrated in FIG. 37, the snapshot request frame 1292 may bevariable in length and include three fields: a view handle field 1294, apath length list field 1296, and a path list field 1298. The view handlefield 1294 may include two bits that provide a “handle” to identify therequested view. In some embodiments, the view handle field 1294 ispopulated using a random 16-bit number or a 16-bit sequence number alongwith a uniqueness check performed on the viewing node 1286 when therequest is formed. The path list length field 1296 includes two bytesthat indicate a length of the path list field 1298. The path list field1298 is variable in length and indicated by the value of the path listlength field 1296. The value of the path list field 1298 indicates aschema path for nodes.

A schema path is a compact description for a data item or container thatis part of a schema resident on the nodes. For example, FIG. 38 providesan example of a profile schema 1300. In the illustrated profile schema1300, a path to data item 1302 may be written as “Foo:bicycle:mountain”in a binary format. The binary format of the path may be represented asa profile binary format 1304, as depicted in FIG. 39. The profile binaryformat 1304 includes two sub-fields: a profile identifier field 1306 anda TLV data field 1308. The profile identifier field 1306 identifieswhich profile is being referenced (e.g., Foo profile). The TLV datafield 1308 path information. As previously discussed TLV data includes atag field that includes information about the enclosed data. Tag fieldvalues used to refer to the Foo profile of FIG. 38 may be similar tothose values listed in Table 19.

TABLE 19 Example tag values for the Foo profile Name Tag animal 0x4301fish 0x4302 fowl 0x4303 medium 0x4304 size 0x4305 bicycle 0x4306 road0x4307 mountain 0x4308 track 0x4309 # of gears 0x430A weight 0x430BUsing Table 19 and the Foo profile of FIG. 38, a binary string in TLVformat representing the path “Foo:bicycle:mountain” may be representedas shown in Table 20 below.

TABLE 20 Example binary tag list for a schema path Profile ID Tag andLength (TL) “bicycle” “mountain” CD:AB:00:00 0D:02 06:43 08:43If the viewing node 1286 desires to receive an entire data set definedin a profile schema (e.g. Foo profile schema of FIG. 39), the viewrequest message 1290 may request a “nil” item (e.g., 0x0D00 TL and anempty length referring to the container.

2. Watch Request

If the viewing node 1286 desires more than a snapshot, the viewing node1286 may request a watch request. A watch request asks the viewed node1288 to send updates when changes are made to the data of interest inviewed node 1288 so that viewing node 1286 can keep a synchronized listof the data. The watch request frame may have a different format thanthe snapshot request of FIG. 37. An embodiment of a watch request frame1310 is illustrated in FIG. 40. The watch request frame 1310 includesfour fields: a view handle field 1312, a path list length field 1314, apath list field 1316, and a change count field 1318. The view handlefield 1312, the path list length field 1314, and the path list field maybe respectively formatted similar to the view handle field 1294, thepath list length field 1296, and the path list field 1298 of thesnapshot request of FIG. 37. The additional field, the change countfield 1318, indicates a threshold of a number of changes to therequested data at which an update is sent to the viewing node 1286. Insome embodiments, if the value of the change count field 1318 is 0, theviewed node 1288 may determine when to send an update on its own. If thevalue of the change count field 1318 is nonzero then after a number ofchanges equal to the value, then an update is sent to the viewing node1286.

3. Periodic Update Request

A third type of view may also be requested by the viewing node 1286.This third type of view is referred to as a periodic update. A periodicupdate includes a snapshot view as well as periodic updates. As can beunderstood, a periodic update request may be similar to the snapshotrequest with additional information determining the update period. Forexample, an embodiment of a periodic update request frame 1320 isdepicted in FIG. 41. The periodic update request frame 1320 includesfour fields: a view handle field 1322, a path list length field 1324, apath list field 1326, and an update period field 1328. The view handlefield 1322, the path list length field 1324, and the path list field1326 may be formatted similar to their respective fields in the snapshotrequest frame 1292. The update period field 1328 is four bytes in lengthand contains a value that corresponds to a period of time to lapsebetween updates in a relevant unit of time (e.g., seconds).

4. Refresh Request

When the viewing node 1286 desires to receive an updated snapshot, theviewing node 1286 may send a view request message 1290 in the form of arefresh request frame 1330 as illustrated in FIG. 42. The refreshrequest frame 1330 essentially resends a snapshot view handle field(e.g., view handle field 1294) from a previous snapshot request that theviewed node 1288 can recognize as a previous request using the viewhandle value in the refresh request frame 1330.

5. Cancel View Request

When the viewing node 1286 desires to cancel an ongoing view (e.g.,periodic update or watch view), the viewing node 1286 may send a viewrequest message 1290 in the form of a cancel view request frame 1332 asillustrated in FIG. 43. The cancel view request frame 1332 essentiallyresends a view handle field from a previous periodic update or watchview (e.g., view handle fields 1310, or 1322) from a previous requestthat the viewed node 1288 can recognize as a previous request using theview handle value in the refresh request frame 1330 and to cancel acurrently periodic update or watch view.

ii. View Response

Returning to FIG. 36, after the viewed node 1288 receives a view requestmessage 1290, the viewed node 1288 responds with a view response message1334. An example of a view response message frame 1336 is illustrated inFIG. 44. The view response message frame 1336 includes three fields: aview handle field 1338, a view request status field 1240, and a dataitem list 1242. The view handle field 1338 may be formatted similar toany of the above referenced view handle fields 1338. Additionally, theview handle field 1338 contains a value that matches a respective viewhandle field from the view request message 1290 to which the viewresponse message 1334 is responding. The view request status field 1340is a variable length field that indicates a status of the view requestand may be formatted according to the status updating format discussedabove. The data item list field 1342 is a variable length field that ispresent when the view request status field 1340 indicates that the viewrequest was successful. When present, the data item list field 1342contains an ordered list of requested data corresponding to the pathlist of the view request message 1290. Moreover, the data in the dataitem list field 1342 may be encoded in a TLV format, as discussed above.

iii. Update Request

As discussed above, in some embodiments, the viewed node 1288 may sendupdates to the viewing node 1286. These updates may be sent as an updaterequest message 1344. The update request message 1344 may include aspecified format dependent upon a type of update request. For example,an update request may be an explicit update request or a view updaterequest field that may be identified by the Message Id 1172.

1. Explicit Update Request

An explicit update request may be transmitted at any time as a result ofa desire for information from another node in the fabric 1000. Anexplicit update request may be formatted in an update request frame 1346illustrated in FIG. 45. The illustrated update request frame 1346includes four fields: an update handle field 1348, a path list lengthfield 1350, a path list field 1352, and a data item list field 1354.

The update handle field 1348 includes two bytes that may be populatedwith random or sequential numbers with uniqueness checks to identify anupdate request or responses to the request. The path list length field1350 includes two bytes that indicate a length of the path list field1352. The path list field 1352 is a variable length field that indicatesa sequence of paths, as described above. The data item list field 1354may be formatted similar to the data item list field 1242.

2. View Update Request

A view update request message may be transmitted by a node that haspreviously requested a view into a schema of another node or a node thathas established a view into its own data on behalf of another node. Anembodiment of a view update request frame 1356 illustrated in FIG. 46.The view update request frame 1356 includes four fields: an updatehandle field 1358, a view handle field 1360, an update item list lengthfield 1362, and an update item list field 1364. The update handle field1358 may be composed using the format discussed above in reference tothe update handle field 1348. The view handle field 1360 includes twobytes that identify the view created by a relevant view request message1290 having the same view handle. The update item list length field 1362includes two bytes and indicates the number of update items that areincluded in the update item list field 1364.

The update item list field 1364 includes a variable number of bytes andlists the data items constituting the updated values. Each updated itemlist may include multiple update items. The individual update items areformatted accordingly to the update item frame 1366 illustrated in FIG.47. Each update item frame 1366 includes three sub-fields: an item indexfield 1368, an item timestamp field 1370, and a data item field 1372.The item index field 1368 includes two bytes that indicate the viewunder which the update is being requested and the index in the path listof that view for the data item field 1372.

The item timestamp field 1370 includes four bytes and indicates theelapsed time (e.g., in seconds) from the change until the update beingcommunicated was made. If more than one change has been made to the dataitem, the item timestamp field 1370 may indicate the most recent or theearliest change. The data item field 1372 is a variable length fieldencoded in TLV format that is to be received as the updated information.

iv. Update Response

After an update is received, a node (e.g., viewing node 1286) may sendan update response message 1374. The update response message 1374 may beencoded using an update response frame 1376 illustrated in FIG. 48. Theupdate response frame 1376 includes two fields: an update handle field1378 and an update request status field 1380. The update handle field1378 corresponds to an update handle field value of the update requestmessage 1344 to which the update response message 1374 is responding.The update request status field 1380 reports a status of the update inaccordance with the status reporting format discussed above.Additionally, a profile using the DMP (e.g., a core profile or a datamanagement profile) may include profile-specific codes, such as thoseenumerated in Table 21 below.

TABLE 21 Example of status codes for a profile including the DMP NameValue Description success 0x0000 Request successfully processedill-formed request 0x0010 Received request was unparseable (e.g.,missing fields, extra fields, etc.) invalid path 0x0011 A path from thepath list of the view or update request did not match a node- residentschema of the responding device. unknown view 0x0012 The view handle inthe update request did handle not match a view on the receiving node.illegal read 0x0013 The node making a request to read a requestparticular data item does not have permission to do so. illegal write0x0014 The node making the request to write a request particular dataitem does not have permission to do so. internal server 0x0020 Theserver could not process the request error because of an internal error.out of memory 0x0021 The update request could not executed because itwould overrun the available memory in the receiving device. continue0x0030 The request was successfully handled but more action by therequesting device may occur.

D. Bulk Transfer

In some embodiments, it may be desirable to transfer bulk data files(e.g., sensor data, logs, or update images) between nodes/services inthe fabric 1000. To enable transfer of bulk data, a separate profile orprotocol may be incorporated into one or more profiles and madeavailable to the nodes/services in the nodes. The bulk data transferprotocol may model data files as collections of data with metadataattachments. In certain embodiments, the data may be opaque, but themetadata may be used to determine whether to proceed with a requestedfile transfer.

Devices participating in a bulk transfer may be generally dividedaccording to the bulk transfer communication and event creation. Asillustrated in FIG. 49, each communication 1400 in a bulk transferincludes a sender 1402 that is a node/service that sends the bulk data1404 to a receiver 1406 that is a node/service that receives the bulkdata 1404. In some embodiments, the receiver may send status information1408 to the sender 1402 indicating a status of the bulk transfer.Additionally, a bulk transfer event may be initiated by either thesender 1402 (e.g., upload) or the receiver 1406 (e.g., download) as theinitiator. A node/service that responds to the initiator may be referredto as the responder in the bulk data transfer.

Bulk data transfer may occur using either synchronous or asynchronousmodes. The mode in which the data is transferred may be determined usinga variety of factors, such as the underlying protocol (e.g., UDP or TCP)on which the bulk data is sent. In connectionless protocols (e.g., UDP),bulk data may be transferred using a synchronous mode that allows one ofthe nodes/services (“the driver”) to control a rate at which thetransfer proceeds. In certain embodiments, after each message in asynchronous mode bulk data transfer, an acknowledgment may be sentbefore sending the next message in the bulk data transfer. The drivermay be the sender 1402 or the receiver 1406. In some embodiments, thedriver may toggle between an online state and an offline mode whilesending messages to advance the transfer when in the online state. Inbulk data transfers using connection-oriented protocols (e.g., TCP),bulk data may be transferred using an asynchronous mode that does notuse an acknowledgment before sending successive messages or a singledriver.

Regardless of whether the bulk data transfer is performed using asynchronous or asynchronous mode, a type of message may be determinedusing a Message Type 1172 in the Application Payload 1146 according theProfile Id 1176 in the Application Payload. Table 22 includes an exampleof message types that may be used in relation to a bulk data transferprofile value in the Profile Id 1176.

TABLE 22 Examples of message types for bulk data transfer profilesMessage Type Message 0x01 SendInit 0x02 SendAccept 0x03 SendReject 0x04ReceiveInit 0x05 ReceiveAccept 0x06 ReceiveReject 0x07 BlockQuery 0x08Block 0x09 BlockEOF 0x0A Ack 0x0B Block EOF 0x0C Error

i. SendInit

An embodiment of a Sendlnit message 1420 is illustrated in FIG. 50. TheSendlnit message 1420 may include seven fields: a transfer control field1422, a range control field 1424, a file designator length field 1426, aproposed max block size field 1428, a start offset field 1430, lengthfield 1432, and a file designator field 1434.

The transfer control field 1422 includes a byte of data illustrated inFIG. 51. The transfer control field includes at least four fields: anAsynch flag 1450, an RDrive flag 1452, an SDrive flag 1454, and aversion field 1456. The Asynch flag 1450 indicates whether the proposedtransfer may be performed using a synchronous or an asynchronous mode.The RDrive flag 1452 and the SDrive flag 1454 each respectivelyindicates whether the receiver 1406 is capable of transferring data withthe receiver 1402 or the sender 1408 driving a synchronous modetransfer.

The range control field 1424 includes a byte of data such as the rangecontrol field 1424 illustrated in FIG. 52. In the illustratedembodiment, the range control field 1424 includes at least three fields:a BigExtent flag 1470, a start offset flag 1472, and a definite lengthflag 1474. The definite length flag 1474 indicates whether the transferhas a definite length. The definite length flag 1474 indicates whetherthe length field 1432 is present in the Sendlnit message 1420, and theBigExtent flag 1470 indicates a size for the length field 1432. Forexample, in some embodiments, a value of 1 in the BigExtent flag 1470indicates that the length field 1432 is eight bytes. Otherwise, thelength field 1432 is four bytes, when present. If the transfer has adefinite length, the start offset flag 1472 indicates whether a startoffset is present. If a start offset is present, the BigExtent flag 1470indicates a length for the start offset field 1430. For example, in someembodiments, a value of 1 in the BigExtent flag 1470 indicates that thestart offset field 1430 is eight bytes. Otherwise, the start offsetfield 1430 is four bytes, when present.

Returning to FIG. 50, the file designator length field 1426 includes twobytes that indicate a length of the file designator field 1434. The filedesignator field 1434 which is a variable length field dependent uponthe file designator length field 1426. The max block size field 1428proposes a maximum size of block that may be transferred in a singletransfer.

The start offset field 1430, when present, has a length indicated by theBigExtent flag 1470. The value of the start offset field 1430 indicatesa location within the file to be transferred from which the sender 1402may start the transfer, essentially allowing large file transfers to besegmented into multiple bulk transfer sessions.

The length field 1432, when present, indicates a length of the file tobe transferred if the definite length field 1474 indicates that the filehas a definite length. In some embodiments, if the receiver 1402receives a final block before the length is achieved, the receiver mayconsider the transfer failed and report an error as discussed below.

The file designator field 1434 is a variable length identifier chosen bythe sender 1402 to identify the file to be sent. In some embodiments,the sender 1402 and the receiver 1406 may negotiate the identifier forthe file prior to transmittal. In other embodiments, the receiver 1406may use metadata along with the file designator field 1434 to determinewhether to accept the transfer and how to handle the data. The length ofthe file designator field 1434 may be determined from the filedesignator length field 1426. In some embodiments, the Sendlnit message1420 may also include a metadata field 1480 of a variable length encodedin a TLV format. The metadata field 1480 enables the initiator to sendadditional information, such as application-specific information aboutthe file to be transferred. In some embodiments, the metadata field 1480may be used to avoid negotiating the file designator field 1434 prior tothe bulk data transfer.

ii. SendAccept

A send accept message is transmitted from the responder to indicate thetransfer mode chosen for the transfer. An embodiment of a SendAcceptmessage 1500 is presented in FIG. 53. The SendAccept message 1500includes a transfer control field 1502 similar to the transfer controlfield 1422 of the Sendlnit message 1420. However, in some embodiments,only the RDrive flag 1452 or the SDrive 1454 may have a nonzero value inthe transfer control field 1502 to identify the sender 1402 or thereceiver 1406 as the driver of a synchronous mode transfer. TheSendAccept message 1500 also includes a max block size field 1504 thatindicates a maximum block size for the transfer. The block size field1504 may be equal to the value of the max block field 1428 of theSendlnit message 1420, but the value of the max block size field 1504may be smaller than the value proposed in the max block field 1428.Finally, the SendAccept message 1500 may include a metadata field 1506that indicates information that the receiver 1506 may pass to the sender1402 about the transfer.

iii. SendReject

When the receiver 1206 rejects a transfer after a Sendlnit message, thereceiver 1206 may send a SendReject message that indicates that one ormore issues exist regarding the bulk data transfer between the sender1202 and the receiver 1206. The send reject message may be formattedaccording to the status reporting format described above and illustratedin FIG. 54. A send reject frame 1520 may include a status code field1522 that includes two bytes that indicate a reason for rejecting thetransfer. The status code field 1522 may be decoded using values similarto those enumerated as indicated in the Table 23 below.

TABLE 23 Example status codes for send reject message Status CodeDescription 0x0020 Transfer method not supported 0x0021 File designatorunknown 0x0022 Start offset not supported 0x0011 Length required 0x0012Length too large 0x002F Unknown errorIn some embodiments, the send reject message 1520 may include a nextstatus field 1524. The next status field 1524, when present, may beformatted and encoded as discussed above in regard to the next statusfield 1188 of a status report frame. In certain embodiments, the sendreject message 1520 may include an additional information field 1526.The additional information field 1526, when present, may storeinformation about an additional status and may be encoded using the TLVformat discussed above.

iv. ReceiveInit

A ReceiveInit message may be transmitted by the receiver 1206 as theinitiator. The ReceiveInit message may be formatted and encoded similarto the Sendlnit message 1480 illustrated in FIG. 50, but the BigExtentfield 1470 may be referred to as a maximum length field that specifiesthe maximum file size that the receiver 1206 can handle.

v. ReceiveAccept

When the sender 1202 receives a ReceiveInit message, the sender 1202 mayrespond with a ReceiveAccept message. The ReceiveAccept message may beformatted and encoded as the ReceiveAccept message 1540 illustrated inFIG. 55. The ReceiveAccept message 1540 may include four fields: atransfer control field 1542, a range control field 1544, a max blocksize field 1546, and sometimes a length field 1548. The ReceiveAcceptmessage 1540 may be formatted similar to the SendAccept message 1502 ofFIG. 53 with the second byte indicating the range control field 1544.Furthermore, the range control field 1544 may be formatted and encodedusing the same methods discussed above regarding the range control field1424 of FIG. 52.

vi. ReceiveReject

If the sender 1202 encounters an issue with transferring the file to thereceiver 1206, the sender 1202 may send a ReceiveReject messageformatted and encoded similar to a SendReject message 48 using thestatus reporting format, both discussed above. However, the status codefield 1522 may be encoded/decoded using values similar to thoseenumerated as indicated in the Table 24 below.

TABLE 24 Example status codes for receive reject message Status CodeDescription 0x0020 Transfer method not supported 0x0021 File designatorunknown 0x0022 Start offset not supported 0x0013 Length too short 0x002FUnknown error

vii. BlockQuery

A BlockQuery message may be sent by a driving receiver 1202 in asynchronous mode bulk data transfer to request the next block of data. ABlockQuery impliedly acknowledges receipt of a previous block of data ifnot explicit Acknowledgement has been sent. In embodiments usingasynchronous transfers, a BlockQuery message may be omitted from thetransmission process.

viii. Block

Blocks of data transmitted in a bulk data transfer may include anylength greater than 0 and less than a max block size agreed upon by thesender 1202 and the receiver 1206.

ix. BlockEOF

A final block in a data transfer may be presented as a Block end of file(BlockEOF). The BlockEOF may have a length between 0 and the max blocksize. If the receiver 1206 finds a discrepancy between a pre-negotiatedfile size (e.g., length field 1432) and the amount of data actuallytransferred, the receiver 1206 may send an Error message indicating thefailure, as discussed below.

x. Ack

If the sender 1202 is driving a synchronous mode transfer, the sender1202 may wait until receiving an acknowledgment (Ack) after sending aBlock before sending the next Block. If the receiver is driving asynchronous mode transfer, the receiver 1206 may send either an explicitAck or a BlockQuery to acknowledge receipt of the previous block.Furthermore, in asynchronous mode bulk transfers, the Ack message may beomitted from the transmission process altogether.

xi. AckEOF

An acknowledgement of an end of file (AckEOF) may be sent in bulktransfers sent in synchronous mode or asynchronous mode. Using theAckEOF the receiver 1206 indicates that all data in the transfer hasbeen received and signals the end of the bulk data transfer session.

xii. Error

In the occurrence of certain issues in the communication, the sender1202 or the receiver 1206 may send an error message to prematurely endthe bulk data transfer session. Error messages may be formatted andencoded according to the status reporting format discussed above. Forexample, an error message may be formatted similar to the SendRejectframe 1520 of FIG. 54. However, the status codes may be encoded/decodedwith values including and/or similar to those enumerated in Table 25below.

TABLE 25 Example status codes for an error message in a bulk datatransfer profile Status code Description 0x001F Transfer failed unknownerror 0x0011 Overflow error

The specific embodiments described above have been shown by way ofexample, and it should be understood that these embodiments may besusceptible to various modifications and alternative forms. It should befurther understood that the claims are not intended to be limited to theparticular forms disclosed, but rather to cover all modifications,equivalents, and alternatives falling within the spirit and scope ofthis disclosure.

Efficient Communication Use Cases and Power Awareness

The efficient IPv6 802.15.4 network protocol and/or the efficientplatform protocol discussed above may enable power-efficient operationin a home environment. As will be discussed below, in one example, suchcommunication may include communicating an IPv6 packet to traverse aparticular preferred network. Additionally or alternatively, propertiesof the manner of communication, such as the type of transportprotocol—TCP or UDP—used to transport the message, may also beselectable. For example, to provide for greater reliability but lesspower savings, TCP may be selected, while to provide greater powersavings but less reliability, UDP may be selected.

Smart Communication Using IPv6 Packet Header Fields

As indicated above, the fields available in an IPv6 packet header may beused in the system of this disclosure to convey information regarding atarget node of a fabric 1000 that is targeted to receive a message. Forinstance, as seen in FIG. 56, a packet header 1600 of an IPv6 packettargeted to a particular node may include a MAC field 1602, a subnetfield 1604, and a fabric ID field 1606. The MAC field 1602 may fill a64-bit area usually understood to represent an Extended UniqueIdentifier (EUI-64). The MAC field 1602 may include an indication of theMAC address of the target node. The subnet field 1604 and the fabric IDfield 1606 may collectively represent an Extended Unique Local Address(EULA). In the EULA of these fields, the fabric ID field 1606 mayindicate the particular fabric 1000 through which the IPv6 packet is tobe sent, while the subnet field 1604 may identify a preferred networkwithin the fabric 1000 over which the target node may preferably receivemessages. In the example of FIG. 56, the subnet field 1604 indicatesthat the target node may preferably receive messages via a particularWiFi network. It should be appreciated that the EULA formed by thefabric ID field 1606 and subnet field 1604 may be used when IPv6 packetsare being sent entirely within one or more connected fabrics and/orservices that serve those fabrics. When the IPv6 packets are to be sentfrom a node of a fabric 1000 to an external IPv6 Internet address, adifferent (e.g., more conventional) IPv6 packet header structure may beemployed.

The EULA information of the subnet field 1604 and the fabric ID field1606 can be used to efficiently communicate IPv6 packets through thefabric 1000 toward a target node. In an example shown in FIG. 57, amessage is sent through the network topology discussed above withreference to FIG. 11. Here, the node 1026 is the sending node and thenode 1036 is the target node. The node 1026 is operating on the 802.15.4network 1022, while the target node 1036 operates on both the 802.15.4network 1022 and the WiFi network 1020. The preferred network of thetarget node 1036 is represented in the example of FIG. 57 to be the WiFinetwork 1020. As such, the IPv6 packets used to send the message fromthe sending node 1026 to the target node 1036 may generally have thecharacteristics shown in the IPv6 packet 1600 of FIG. 56.

The various nodes 1026, 1028, 1030, 1034, and 1042 are shown in FIG. 57to communicate the message from the sending node 1026 to the target node1036. When there is only one network over which to send the message, themessage may be communicated through that network. This is the case withthe nodes 1026, 1028, and 1030 in the example of FIG. 57. When themessage reaches a node that operates on more than one network, such asthe node 1034, however, that node may use the subnet field 1604 todetermine which network to use to communicate the message further towardthe target node 1036.

A flowchart 1650 of FIG. 58 illustrates an example of a method for usingthe subnet field 1604 of a packet header 1600 to communicate the IPv6packet toward a target node. In the method, a node that operates on twonetworks (e.g., node 1034, which operates on both the WiFi network 1020and the 802.15.4 network 1022) may receive an IPv6 packet (block 1652).The node may analyze the subnet field 1604 of the IPv6 packet header1600 to determine which network is the most proper network to use toforward the IPv6 packet toward the target node. The subnet field 1604may indicate, for example, that the message is to be received by thetarget node (e.g., the node 1036) on the WiFi network 1020. Thereceiving node (e.g., node 1034) then may communicate the IPv6 packettoward the target node (e.g., node 1036) over the network indicated bythe subnet field 1604 (e.g., the WiFi network 1020) (block 1654).

In some examples, the network over which the IPv6 packet has beenreceived may be different from the network indicated by the subnet field1604. In FIG. 57, for example, the node 1034 receives the message overthe 802.15.4 network 1022. When the subnet field 1604 indicates that theWiFi network 1020 is the preferred network to be used to send the IPv6packet, however, the node 1034 may communicate the IPv6 packet over theWiFi network 1020 instead. In this way, the subnet field 1604 may enablea target node to have a preferred network over which to receivemessages. In the example of FIG. 57, the target node 1036 may be analways-on electronic device that may communicate more rapidly or morereliably over the WiFi network 1020 than the 802.15.4 network 1022. Inother examples, the target node 1036 may be a battery-powered sleepydevice that would be better served to receive messages over the 802.15.4network 1022. Under such an example, even though the target node 1036could receive messages via the WiFi network 1020, by receiving themessages via the 802.15.4 network 1022 as may be indicated by a subnetfield 1604, the target node 1036 may conserve power. Thus, the EULA ofthe IPv6 packet header 1600 (e.g., the fabric ID field 1606 and thesubnet field 1604) may be used to promote efficient message transferthrough a fabric.

Selection of the Transport Protocol or Preferred Target Network Based onthe Desired Reliability of the Message

Judicious selection of the transport protocol (e.g., TCP or UDP) and/ora preferred target node network used to send the IPv6 packets may alsolead to efficient network usage. Indeed, while TCP is more reliable thanUDP, the reliability of TCP stems from its use of handshaking andacknowledgments when transmitting messages, many of which are absent inUDP. The additional reliability of TCP, however, may increase the costof sending a message in terms of power consumed. Indeed, there is anadditional cost in power due to the handshaking and acknowledgments ofTCP. In addition, using TCP will cause dropped packets to be resentuntil they have been confirmedly received, consuming additional power atall devices that suffer dropped packets.

As such, it may be desirable to send messages by UDP unless there arereasons that reliability is preferred over power efficiency. Forinstance, as shown in a flowchart 1670 of FIG. 59, one of the devices ona fabric 1000 may generate a message (block 1672). The device mayconsider one or more reliability factors relating to a desiredreliability of the message (block 1674). This consideration of the oneor more reliability factors may take place in the application layer 102or the platform layer 100 of the OSI stack 90 running on the device. Ineither case, the reliability factor(s) that the device may consider mayinclude (1) a type of the message generated at block 1672, (2) a type ofthe network over which the message is going to be sent, (3) a distanceover which the message may travel through the fabric, (4) a powersensitivity of the target node and/or the transmitting nodes that aregoing to be used to communicate the message to the target node, and/or(5) a target end node type (e.g., whether a device or a service). Insome embodiments, only one factor may be considered. Moreover, the listof reliability factors discussed here is not intended to be exhaustive,but rather to provide examples for deciding whether reliability or powersavings may be more desirable when sending a message.

A first factor that may affect the desired reliability of the transportprotocol is the type of the message that is going to be sent. A veryhigh reliability may be desired when the message is an alarm message,such as a message indicating that a hazard has been detected. A highreliability may be less valuable than power savings, however, when themessage represents sensor data or certain device status data.

A second factor that may affect the desired reliability of the transportprotocol is the type of network over which the message is to be sent.When the message will primarily traverse an 802.15.4 network, forexample, this may imply that power savings may be more beneficial thanreliability. When the message will primarily or entirely traverse a WiFinetwork, however, this may imply that the power savings may be lessvaluable and reliability may be more valuable.

A third factor that may affect the desired reliability of the transportprotocol is the distance over which the message may travel through thefabric 1000 to reach the target node. The distance may represent, forinstance, the number of “hops” to reach the target node, the number ofdifferent types of networks that may be traversed to reach the targetnode, and/or an actual distance through the network.

A fourth factor that may affect the desired reliability of the transportprotocol is the power sensitivity of the devices that may be used tocommunicate the message to the target node. When all or substantiallyall of such devices are always-on or are supplied by an external powersource, higher reliability may be preferable to power savings. When oneor many of the devices are low-power, sleepy, and/or battery powereddevices, power savings may be preferable when the message is notespecially urgent.

A fifth factor that may affect the desired reliability of the transportprotocol is the type of the target end node of the message. In oneexample, when the target end node is a service, whether local or remote,a higher reliability may be desired. Thus, in this case, TCP may bepreferred over UDP. In another example, a higher reliability may bepreferred when the target end node is a remote service, but lessreliability and greater power savings may be called for when the targetend node is a local service. In other examples, the type of service maybe considered. That is, for some services, reliability may be preferredover power savings, while for other services, power savings may bepreferred over reliability. To provide just one example, to communicatewith a service used to provide weather information, a relatively lowerreliability may be desired as compared to power savings. On the otherhand, to communicate with a service used to provide a software update,higher reliability may be preferred over power savings.

The device may consider one or more of these factors in any suitableway. In one example, the factors may be assigned a weight andreliability determination may be based on the total weighting of thefactors. In other examples, certain factors may have a higher prioritythan other factors. In such an example, an urgent message may always beconsidered to have more desired reliability over power savings, whilethe desirability of reliability for non-urgent messages may depend onother factors. As such, when power savings is desired over reliability(decision block 1676), the device may send the message via UDP (block1678) to save power despite lower reliability. When more reliability isdesired over power savings (decision block 1676), the device may sendthe message via TCP (block 1680) to have increased reliability despitehigher power consumption.

Although the above method has been discussed with reference to aselection of sending the message using TCP or UDP, it should beappreciated that the present communication system may efficiently adjustany number of properties of the manner of communication to balancedesired reliability with power consumption. For example, in someembodiments, when a higher reliability is desired, a higher-powernetwork (e.g., WiFi) may be preferred, while when a lower reliabilityand higher power savings is desired, a lower-power network (e.g.,802.15.4) may be preferred. The sending node may, for example, select adifferent preferred network to note in the subnet field 1604 of the IPv6packet header 1600, thereby causing the message to be communicated, whenpossible, through that selected network.

Additional Use Cases

The fabric 1000 of connected devices discussed above may be used in avariety of manners. One example may involve using one device to invoke amethod on another device. Another example may involve propagating amessage, such as a hazard alarm, over various devices of the fabric. Itshould be understood that these use cases are intended to provideexamples and are not intended to be exhaustive.

Invoking a Method from One Device on Another

In one case, a device in one area of the fabric 1000 may invoke aparticular method on another compatible device. One example appears in adiagram 1700 of FIG. 60. The diagram 1700 illustrates interactionsbetween a first device 1702 and a second device 1704, as mediated by adirectory device (DDS) 1706. The directory device (DDS) 1706 may issue aDDS service broadcast 1708 to the various devices on the fabric,including the first device 1702 and the second device 1704. In response,the directory device (DDS) 1706 may receive a list of all methods and/orprofiles the various devices of the fabric 1000 support.

When one of the devices of the fabric, such as the first device 1702desires to perform a method (shown in FIG. 60 as a method n), the firstdevice 1702 may query the directory device (DDS) 1706 with acorresponding query message 1710 (e.g., GetProperty(supports-n)). Thedirectory device (DDS) 1706 may reply with the devices that support sucha property—here, replying with a message 1712 indicating that the seconddevice 1704 supports the desired method. Now in possession of thisinformation, the first device 1702 may invoke the method in a message1714 to the second device 1704. The second device 1704 then may issue areply 1716 with an appropriate response.

The method invoked by the first device 1702 on the second device 1704may be any of a number of methods that may be useful to a home network.In one example, the first device 1702 may request environmental sensordata from the second device 1704. The environmental sensor data mayindicate motion, temperature, humidity, and so forth. The environmentalsensor data may be used by the first device 1702 to determine occupancyfor security, for example, or to determine various temperaturescurrently located around a house. In another example, the first device1702 may request user interface input information from the second device1704. For instance, the first device 1702 may request an indication ofrecent thermostat temperature setpoints to ascertain informationregarding the recent desired comfort settings of the occupants.

Propagating a Message to Various Devices of the Fabric

In some situations, it may be desirable to propagate a message tomultiple devices of the fabric. For example, as shown in a diagram 1720of FIG. 61, several devices 1722, 1724, 1726, and 1728 may be used topropagate a hazard alarm message. Indeed, the hazard alarm message maybe propagated even though one or more of the various devices 1722, 1724,1726, and 1728 may be low-power, “sleepy” devices. In the example ofFIG. 61, the device 1722 is a hazard detector (e.g., a smoke detector)in the garage, the device 1724 is a hazard detector (e.g., a smokedetector) in the dining room, the device 1726 is a smart doorbell at thefront door, and the device 1728 is a thermostat in the hallway.

The action of the diagram 1720 begins when an event 1730 (e.g., fire) isdetected by the garage device 1722. The garage device 1722 may propagatea network wake message 1732 to the dining room device 1724, which mayissue a reply 1734 accordingly. The dining room device 1724 maytemporarily wake up from its sleepy state to an awake, always-on state.The dining room device 1724 may also propagate a network wake message1736 to the front door device 1726, which may reply 1738 likewise whilepropagating another network wake message 1740 to the hallway device1728.

Having woken the devices of the fabric, the garage device 1722 mayoutput an alarm 1744 associated with the event 1730 and may issue analarm notification message 1746 to the dining room device 1724. Thealarm notification message 1746 may indicate the type of event and theoriginating device (e.g., event occurring in the garage), among otherthings. The dining room device 1724 may output a corresponding alarm1748 and forward an alarm notification message to the front door device1726, which may itself begin to output an alarm 1752. The front doordevice 1726 may also forward an alarm notification message to thehallway device 1728.

The hallway device 1728 may display an interface message 1756 to enablea user to respond to the alarm. In the meantime, messages may continueto be propagated across the fabric. These include additional networkwake and reply messages 1758, 1760, 1762, 1764, and 1766, and additionalalarm notification messages 1768, 1770, and 1772. When a user providesuser feedback 1774 on the hallway device 1728 requesting that the alarmbe silenced (in the understanding, for example, that the alarm is falseor due to non-hazardous conditions), the hallway device 1728 may respondby sending an alarm silence message 1776 that may be propagated over thefabric 1000 to all of the devices. The alarm silence message 1776 mayreach the front door device 1726, which may silence its alarm 1778 andissue a further alarm silence message 1780 to the dining room device1724. In response, the dining room device 1724 may silence its alarm1782 and issue a further alarm silence message to the garage device1722, which may in turn silence its alarm 1786.

After causing the devices 1726, 1724, and 1722 to silence their alarms,the hallway device 1728 may cause the devices 1726, 1724, and 1722 toreenter a sleepy, low-power state. Specifically, the hallway device 1728may issue network sleep message 1790 to the front door device 1726,which may enter a sleepy state after issuing a network sleep message1792 to the dining room device 1724. The dining room device 1724 maycorrespondingly enter a sleepy state after issuing a network sleepmessage 1794 to the garage device 1722. Upon receipt of the networksleep message 1794, the garage device 1722 may enter the low-power,sleepy state.

Joining or Creating a Fabric

The protocols discussed above can be used to join or create a fabric1000 of devices in a home network or similar environment. For example,FIGS. 62-64 relate to a first method in which a new device joins anexisting fabric 1000 through another device of the fabric 1000 that isconnected to a service (e.g., via the Internet). FIGS. 65-67 relate to asecond method in which a new device joins an existing fabric 1000 orcreates a new fabric 1000 through a peer-to-peer connection with anotherdevice regardless of whether either device is connected to anotherservice. The following examples relate to joining a fabric 1000 with anew device that may not have a user interface with a native display, andas such may involve assistance from a third-party client device (e.g., amobile phone or tablet computer). In other embodiments, such as those inwhich the new device includes a user interface with a native display,the activities described below as being carried out on a third-partyclient device may instead take place on the new device.

Joining or Creating a Fabric Using an Internet Connection to a Service

Turning first to a flowchart 1800 shown in FIGS. 62-64, a user may joina new device to a fabric 1000 by opening the box in which the device hasbeen sold (block 1802) and obtaining instructions to install anapplication (block 1804) on a third-party client device (e.g., a mobilephone or tablet computer). The application may be installed on theclient device (block 1806) and the user may log into a service accountrelated to the fabric 1000 where the user may select the particularfabric 1000 the new device is to join (block 1808). For instance, theuser may install a Nest® application and may log into a Nest® serviceaccount associated with a Nest® Weave™ fabric. The application on theclient device may obtain information associated with a serviceconfiguration of the fabric 1000 (block 1810). The informationassociated with the service configuration of the fabric 1000 mayinclude, for example:

-   -   a service node identification (e.g., an EUI-64 or EULA);    -   a set of certificates that may serve as trust anchors for the        service (e.g., a fabric authentication token);    -   a globally unique account identification associated with the        user's account;    -   a Domain Name Service (DNS) host name identifying the entry        point for the service; and/or    -   an opaque account pairing token that may be used by the new        device to pair with the user's account.

The user may also elect, via the application on the client device, toadd a new device to the fabric 1000 (block 1812). Based on whether thereis currently an existing fabric 1000 associated with the user or basedon any other suitable criteria (decision block 1814), the applicationmay choose to create a new fabric 1000 (block 1816) or to add the newdevice to an existing fabric 1000 (block 1818).

When the application chooses to add the new device to an existing fabric1000 (block 1818), the application may determine whether the devices ofthe network are in an awake rather than sleepy state (decision block1820), waking the devices (block 1822) if not awake. The user may selecta particular existing device of the network to use in a joining processby, for example, pressing a button (block 1824). The existing device mayprovide fabric joining information to the application on the clientdevice (block 1826). For instance, the application on the client devicemay establish a secure session with the existing device using a fabric1000 authentication token. The application may use requests (e.g.,GetNetworkConfiguration and/or aGetFabricConfiguration) to obtain fromthe existing device network configuration information and/or fabric 1000configuration information. The application may save this information forlater use.

The application may further instruct the user to wake the new device(block 1828) by, for example, pressing a button on the new device (block1830). The method then may progress to block (A) 1832, which continueson FIG. 63. Here, the application on the client device may instruct theexisting device to connect to the new device (block 1834). For example,the application may establish a new secure session to the existingdevice using a fabric authentication token, and over this new sessionmay send a request (e.g., ConnectOtherDevice) to the existing device.Meanwhile, the new device may have set up an 802.15.4 “joining network”specific to the purpose of joining with the existing device. Thus, therequest of block 1834 may specify that the application wishes theexisting device to connect to the new device via an 802.15.4 networkconnection (e.g., the 802.15.4 joining network created by the newdevice). The existing device then may perform a scan of nearby 802.15.4networks looking for the network created by the new device. Once found,the existing device may leave the existing fabric, join the new 802.15.4joining network, and probe the 802.15.4 joining network by attempting toconnect to a rendezvous address (which may be previously specified bythe software or firmware of the existing device or by the application onthe client device). Once a connection to the new device is established,the existing device may respond to the request to connect to the newdevice (e.g., ConnectOtherDevice) from the application on the clientdevice with a reply of success. From this point forward, messagesprovided to the new device from the application may be carried by proxythrough the existing device via the 802.15.4 joining network. That is,the new device may be connected to the existing device via the 802.15.4joining network, the existing device may be connected to the servicenode via WiFi (and/or an Internet connection), and the application onthe client device may be connected to the service. In this way, theapplication may connect to the new device through the existing fabric,and the existing device may only use single WiFi connection and a single802.15.4 connection (thereby reducing avoiding using in the existingdevice multiple receivers and transmitters per network type, which mayreduce device cost and power consumption).

Alternatively, when a new fabric 1000 is to be created, the applicationon the client device may connect directly to the new device using a WiFiconnection. Thus, the application on the client device may instruct theuser to switch to a WiFi connection (block 1836). The user may switchWiFi networks on their client device to establish a peer-to-peer WiFiconnection with the new device (block 1838). For example, the new devicemay have associated with it a unique WiFi SSID name on the back of thenew device. The application on the client device may probe for the newdevice by repeatedly attempting to connect to a previously determinedrendezvous address (e.g., as provided to the application by theconfiguration information from the service or as encoded in theapplication).

With either of these connections established, the application on theclient device may detect the new device and display a serial numberprovided by the new device (block 1840). At this time, the applicationmay also validate that the new device has installed on it certainsecurity features identifying the device as authentically validated andhaving proper permissions to join the fabric. These security featuresmay be the same as or in addition to the DTLS security certificatesdiscussed above.

Using either connection, the user may facilitate an authenticationprocedure when the application on the client device instructs the userto scan a QR code or other code associated with the new device (e.g.,printed on the new device or on a card provided with the new device)(block 1842). The user may enter the code by scanning or typing the codeinto the application (block 1844). This code information may be providedto the new device, which may use the code to confirm that theapplication is being used authentically by a user in possession of thenew device. The new device may, for example, validate the code using abuilt-in check digit. The new device may indicate when the code has beenentered incorrectly with a corresponding reply. The application mayestablish a secure session with the new device using any suitableprotocol, including the Weave PASE protocol, using the supplied pairingcode as a password (block 1848). Having established the secureconnection to the new device, the application on the client device mayissue a request to arm a failsafe regimen on the new device (e.g.,ArmConfigurationFailsafe) (block 1850). By arming the failsafe regimen,the new device may revert to certain original configurations if thejoining process does not complete by some timeout value. The applicationmay also determine whether the new device belongs to another existingfabric 1000 by issuing a suitable request (e.g., GetFabricState)(decision block 1852). If so, the application may instruct the newdevice to leave the other existing fabric 1000 by issuing anotherrequest (e.g., LeaveFabric) (block 1854).

In a case in which the new device is to form a new fabric 1000 with theexisting device (decision block 1856), the application may instruct thenew device to enumerate a list of WiFi networks visible to the newdevice (e.g., via an EnumerateVisibleNetworks request) (block 1858).Upon instruction from the application (block 1860), the user then mayselect from among these networks or may enter the WiFi network that thenew device is to join (block 1862). The user may also enter anappropriate password to join the WiFi network (block 1864). The methodmay further progress to block (B) 1866, which continues on FIG. 64. Theapplication may send the WiFi network configuration information to thenew device (e.g., via an AddNetwork request) (block 1868), and theapplication may instruct the new device to test the connection (e.g.,via a TestNetwork request) by attempting to reach the service on theInternet (block 1870). The application may indicate to the user that thenetwork connection is being confirmed (block 1872) and the new devicemay subsequently confirm its connection to the application (block 1874).

With the new device now connected to the Internet via the WiFiconnection, if a new fabric 1000 is being created (block 1876), theapplication may instruct the user to return to the fabric 1000 (e.g.,the user's home) WiFi connection (block 1878). The user may change theWiFi network being used by the client device to the WiFi connection usedby the fabric 1000 (block 1880).

Whether creating a new fabric 1000 or joining an existing one, theapplication may instruct the new device to do so at this point (block1882). That is, the application may instruct the new device to create anew fabric 1000 (e.g., via a CreateFabric request) or may instruct thenew device to join the existing fabric 1000 (e.g., via aJoinExistingFabric request). In the case of joining an existing fabric,the application may inform the new device of the existing device (e.g.,via a RegisterNewFabricMember request to the new device). In eithercase, the application may configure the new device to communicate withthe service (e.g., the Nest® service) by sending a request (e.g., aRegisterService request) that contains service configuration information(e.g., Weave™ Service Configuration information).

Using the service configuration information, the new device may registerwith the service (block 1884). For example, the new device may connectto the service using a service node ID and DNS name from the serviceconfiguration information. The new device may register with the serviceusing a certificate installed on the new device and a private key. Thenew device may send a message (e.g., a PairDeviceToAccount message) tothe service containing the service account identification associatedwith the fabric 1000 and an account pairing token obtained from theservice configuration information. Using this information, the servicemay validate the account pairing token and may associate the new devicewith the user's service account associated with the fabric. At thispoint, the new device may be understood by the service to form a part ofthe fabric 1000 and may appear as an associated device when the userlogs into the service. The service may respond to the message from thenew device (e.g., the PairDeviceToAccount message), may destroy its copyof the account pairing token, and may respond to the message previouslysent to the application (e.g., the RegisterService request).

In response, to finalize the joining of the new device to the existingfabric 1000 or the new fabric, the application may cancel the joiningfailsafe mechanism by sending a corresponding message to the new device(e.g., a DisarmConfigurationFailsafe request) (block 1886). The newdevice thereafter may receive this request to disarm the configurationfailsafe (block 1888). Pairing of the new device to the existing devicein either a new fabric 1000 or an existing fabric 1000 may now beconsidered complete. The application on the client device thus may offerthe user instructions for additional setup settings (block 1890) thatthe user may select from (block 1892). These may include, for example,continuing to pair additional devices or exiting setup.

Joining or Creating a Fabric without a WiFi Connection to the Internet

A new device may join or create a fabric 1000 without necessarily havingaccess to a WiFi connection to a service or the Internet. For example,as shown in FIGS. 65-67, such a connection may be formed using othernetwork connection without facilitation by a service (e.g., over just an802.15.4 network connection). This section describes the actions andevents that may happen during the process of joining a new device in adevice-to-device fabric. As used herein, a “device-to-device fabric” isa network of two or more fabric 1000 devices connected via a singlenetwork interface (e.g., via 802.15.4 interfaces only). Devices in adevice-to-device fabric 1000 are not necessarily connected to a WiFinetwork and thus may not talk to an application (e.g., web or mobile)running on a client device (as in FIGS. 62-64) or to a service on theInternet (e.g., the Nest® service).

In some cases, device-to-device fabrics may be easier to form than WiFifabrics, involving user participation only in that the may user pressbuttons on two devices within a short period of time. Thedevice-to-device joining process described by FIGS. 65-67 may supportboth the creation of a new device-to-device fabric 1000 using twoindependent devices, as well as the joining of a new independent deviceto an existing device-to-device fabric. Device-to-device joining canalso be used to remove a device from an existing device-to-device fabric1000 and join it to another device-to-device fabric. This latterscenario may become particularly useful when a user acquires a useddevice that wasn't properly severed from its old device-to-devicefabric.

Note that the device-to-device joining process may not be used to join anew device into an existing WiFi fabric 1000 in some embodiments. Forthis, the user may follow the WiFi joining process discussed above withreference to FIGS. 62-64. Also, the device-to-device joining process maynot be used to join a device that is already a member of a WiFi fabric1000 into a device-to-device fabric. Thus, in the case where a useracquires a used device that wasn't properly severed from its originalWiFi fabric, the user may perform a factory reset on the device beforeproceeding with the device-to-device fabric 1000 joining process.

The device-to-device joining process may begin when, as shown by aflowchart 1900 of FIG. 65, a first device (e.g., Device 1) of twodevices that are to be joined is activated (block 1902). For example,based on instructions in the sales box of the first device, a user maypress a button on the first device. Here, if the user is adding a deviceto an existing fabric, the user may be instructed to press the button onthe device to be added. If the user is creating a new fabric 1000 out oftwo independent devices, the user may select either device as the firstdevice. Also, if the first device is a member of a WiFi fabric, thefirst device may take no further action and the joining procedure stops.When the first device is a member of a WiFi fabric, the first device maybe disassociated with the WiFi fabric 1000 before joining thedevice-to-device network (e.g., via a factory reset).

When not a member of an existing WiFi fabric, the first device (e.g.,Device 1) may begin certain initialization procedures when activated asin block 1902. For example, Device 1 may start a counter that incrementswith time (e.g., multiple times a second). This counter will later beused to determine which device is of two device has priority inestablishing a fabric, if appropriate. Device 1 also may create an802.15.4 wireless network, which may be called the 802.15.4 joiningnetwork (block 1904). This 802.15.4 joining network may be a generallyunique, unsecured network. For example, the 802.15.4 joining network mayuse a generally unique ELoWPAN 110 network name containing the followinginformation: (a) a string identifying the network as a joining network,(b) the first device's node id, and (c) a flag indicating whether thedevice is part of a fabric. When the joining network is established,Device 1 may also assign itself two IPv6 addresses in the joiningnetwork (block 1906). These may include, for example: (a) an IPv6 ULA orEULA with a distinct prefix, which may be called the rendezvous prefix,and an interface identifier derived from the device's MAC address, and(b) an IPv6 ULA or EULA with the rendezvous prefix and an interfaceidentifier of 1, which may be called the rendezvous address.

Device 1 then may continuously scan for an 802.15.4 network created byanother device (block 1908). Indeed, in parallel to or after the acts ofblocks 1902-1908, a second device (Device 2) may perform the above actsitself (block 1910). Either Device 1 or Device 2 may detect the other'sjoining network (block 1912). Depending on certain characteristics ofthe device—Device 1 or Device 2—that is first to detect the other, thedevices may perform an initiating device process (e.g., as shown in FIG.66) or a responding device process (e.g., as shown in FIG. 67). That is,when one of the devices discovers the other's joining network, thedevice compares the information contained in the joining network namewith its own information and may takes action as follows: (a) if thedevice is an independent device and the other device is a member of afabric, the device may performs the acts shown in the initiating deviceprocess of FIG. 66; or (b) if the device is a member of a fabric 1000and the other device is an independent device, the device may performthe acts shown by the responding device process of FIG. 67. If neitherdevice is a member of a fabric, or if both devices are members of afabric, the device that detects the other device's joining network may(a) compare its node id to the node id of the other device and (b) ifthe device's node id is less than the node id of the other device, thedevice may perform the acts of the acts shown in the initiating deviceprocess of FIG. 66. If neither device is a member of a fabric, or ifboth devices are members of a fabric, the device that detects the otherdevice's joining network may (a) compare its node id to the node id ofthe other device and (b) if the device's node id is greater than thenode id of the other device, may perform the acts shown by theresponding device process of FIG. 67.

The device that performs the initiating device process of FIG. 66 may beeither Device 1 or Device 2, as mentioned above. As such, the devicethat performs the initiating device process of FIG. 66 will now bereferred to as the “initiating device.” Likewise, the device thatperforms the responding device process of FIG. 67 may be the device notoperating as the initiating device, and may be either Device 1 or Device2, as mentioned above. As such, the device that performs the respondingdevice process of FIG. 67 will now be referred to as the “respondingdevice.”

As seen in a flowchart 1920, the initiating device process of FIG. 66may begin when the initiating device terminates its joining network andconnects to the joining network created by the responding device (block1922). The initiating device may assign itself a IPv6 ULA or EULA withthe rendezvous prefix and an interface identifier derived from its MACaddress (block 1924). The initiating device may send a Solicit Joiningmessage to the responding device at its rendezvous address. The SolicitJoining message from the initiating device may include the followinginformation: (a) a numeric discriminator value set to the value of thecounter that was started when the device and woke up, and (b) a flagindicating whether the device is already a member of a fabric. Theinitiating device then may wait for a response message from theresponding device, receiving either a Join Existing Fabric request or aSolicit Joining request (block 1928).

When the initiating device receives a Join Existing Fabric request, theinitiating device may leave its current fabric, if appropriate, and mayreinitialize itself as an independent device, and may make itself partof the existing fabric 1000 with the responding device, using theinformation in the Join Existing Fabric request (block 1930). Theinitiating device may send a Join Existing Fabric response to theresponding device indicating it is now a member of the existing fabric1000 (block 1932).

When the initiating device receives a Solicit Joining request, theinitiating device may respond in different manners depending on whetherit is an independent device or a member of an existing fabric, but ineither case may send fabric 1000 information in a Join Existing Fabricrequest (block 1934). For example, when the initiating device is anindependent device, the initiating device may create a new fabric 1000by generating a new fabric id and corresponding fabric securityinformation, may make itself part of the new fabric, and may send a JoinExisting Fabric request to the responding device. The Join ExistingFabric request may contain the information for the new fabric.Otherwise, if the device is a member of a fabric, the device may send aJoin Existing Fabric request to the responding device that contains theinformation for the existing fabric 1000 that the initiating device is amember of. The initiating device then may wait for, and receive, a JoinExisting Fabric response from the responding device when the respondingdevice joins the fabric 1000 of the initiating device.

The responding device process of FIG. 67 describes a manner in which theresponding device may behave in relation to the initiating device. Theresponding device process of FIG. 67 is described by a flowchart 1950.The flowchart 1950 begins when the responding device receives a SolicitJoining message from the initiating device (block 1952).

If the responding device is an independent device and is not in anexisting fabric 1000 (decision block 1954), the responding device maycreate a new fabric 1000 by generating a new fabric id and correspondingfabric security information (block 1956). The responding device may makeitself part of the new fabric 1000 (block 1958). The responding devicethen may send a Join Existing Fabric request to the initiating devicethat contains the information for the new fabric 1000 of the respondingdevice (block 1960). The responding device may wait for the JoinExisting Fabric response from the initiating device.

Otherwise, upon receipt of the Solicit Joining message (block 1952), ifthe responding device is in an existing fabric 1000 (decision block1954), the responding device may adopt a different behavior.Specifically, if the responding device is in a fabric, the respondingdevice may inspect the Solicit Joining message (block 1962). Theresponding device may inspect the discriminator value (the counter valueof the initiating device) and the ‘is member of fabric’ flag in theSolicit Joining

Otherwise, if the Solicit Joining message indicates that the initiatingdevice is not a member of a fabric 1000 or if the discriminator value isgreater than or equal to the counter started by the responding devicewhen it woke up (decision block 1964), the responding device may send aJoin Existing Fabric request to the initiating device that contains theinformation for the fabric 1000 of the responding device (block 1974).The responding device may wait for the Join Existing Fabric responsefrom the initiating device.

If the Solicit Joining message indicates that the initiating device is amember of a fabric 1000 or if the discriminator value is less than thecounter started by the responding device when it woke up (decision block1964), the responding device may leave its current fabric 1000 andreinitializes itself as an independent device (block 1966). Theresponding device may further send a Solicit Joining message to theinitiating device (block 1968) and may wait for a Join Existing Fabricrequest from the initiating device. Upon receiving the Join ExistingFabric request from the initiating device (block 1970), the respondingdevice may make itself part of the new fabric 1000 using the informationin the Join Existing Fabric request (block 1972). The responding devicemay also send a Join Existing Fabric response indicating it is now amember of the existing fabric 1000 of the initiating device.

The specific embodiments described above have been shown by way ofexample, and it should be understood that these embodiments may besusceptible to various modifications and alternative forms. It should befurther understood that the claims are not intended to be limited to theparticular forms disclosed, but rather to cover modifications,equivalents, and alternatives falling within the spirit and scope ofthis disclosure.

What is claimed is:
 1. A tangible, non-transitory computer-readablemedium comprising instructions configured to be executed by a firstelectronic device when communicably coupled to other electronic devicesof a fabric of devices in a home environment, the instructionscomprising instructions to: receive an Internet Protocol version 6(IPv6) message at the first electronic device from a second electronicdevice over a first network of the fabric of devices, wherein themessage is bound for a target electronic device; identify an ExtendedUnique Local Address encoded in an IPv6 header of the message, whereinthe Extended Unique Local Address indicates that a second network ispreferred to reach the target electronic device; and communicate themessage through the fabric of devices toward the target electronicdevice using a second network based at least in part on the ExtendedUnique Local Address.
 2. The computer-readable medium of claim 1,wherein the Extended Unique Local Address of the IPv6 packet headercomprises a first field identifying the fabric of devices and a secondfield identifying that the second network is preferred to reach thetarget electronic device, wherein the first field comprises 48 bits andthe second field comprises 16 bits.
 3. The computer-readable medium ofclaim 2, wherein the IPv6 header of the message comprises a third fieldcomprising an extended unique identifier of the target electronicdevice, wherein the third field comprises 64 bits.
 4. Thecomputer-readable medium of claim 1, wherein the message is communicatedthrough the fabric of devices toward the target electronic device usingsecond network based at least in part on the Extended Unique LocalAddress if the second network is available to the first device.
 5. Thecomputer-readable medium of claim 1, wherein the message is communicatedthrough the fabric of devices toward the target electronic device usingsecond network based at least in part on whether the first device is analways-on device powered by an external power source.
 6. A device,comprising: a network interface configured to receive an InternetProtocol version 6 (IPv6) message from a second electronic device of afabric of devices over a first network of the fabric of devices, whereinthe message is bound for a target electronic device; and a processorconfigured to identify an Extended Unique Local Address encoded in anIPv6 header of the message, wherein the Extended Unique Local Addressindicates that a second network is preferred to reach the targetelectronic device, wherein the network interface is configured toselectively communicate the message through the fabric of devices towardthe target electronic device using a second network based at least inpart on the Extended Unique Local Address.
 7. The device of claim 6,wherein the processor is configured to identify the Extended UniqueLocal Address of the IPv6 packet header via a first field identifyingthe fabric of devices and a second field identifying that the secondnetwork is preferred to reach the target electronic device, wherein thefirst field comprises 48 bits and the second field comprises 16 bits. 8.The device of claim 7, wherein the processor is configured to identify athird field of the IPv6 header of the message as comprising an extendedunique identifier of the target electronic device, wherein the processoris configured to identify the third field as comprising 64 bits.
 9. Thedevice of claim 6, wherein the network interface is configured toselectively communicate the message through the fabric of devices towardthe target electronic device using the second network based at least inpart on whether the second network is available to the device.
 10. Thedevice of claim 6, wherein the network interface is configured toselectively communicate the message through the fabric of devices towardthe target electronic device using the second network based at least inpart on whether the first device is an always-on device powered by anexternal power source.
 11. The device of claim 6, wherein the networkinterface is configured to selectively communicate the message throughthe fabric of devices toward the target electronic device using thesecond network based at least in part on whether the first device is analways-on device powered by an external power source.
 12. The device ofclaim 6, wherein the network interface is configured to selectivelycommunicate the message through the fabric of devices toward the targetelectronic device using the second network based at least in part on oneor more reliability factors relating to a desired reliability of themessage.
 13. The device of claim 6, wherein the network interface isconfigured to selectively communicate the message through the fabric ofdevices toward the target electronic device using the second networkbased at least in part on a type of the message that to be sent, a typeof network over which the message is to be sent, a distance over whichthe message may travel through the fabric to reach the target device,power sensitivity of devices used to communicate the message to thetarget device, and a type of the target device as the one or morereliability factors relating to a desired reliability of the message.14. A method, comprising: receiving, at a network interface of a firstelectronic device, an Internet Protocol version 6 (IPv6) message from asecond electronic device of a fabric of devices over a first network ofthe fabric of devices, wherein the message is bound for a targetelectronic device; identifying, via a processor of the first electronicdevice, an Extended Unique Local Address encoded in an IPv6 header ofthe message, wherein the Extended Unique Local Address indicates that asecond network is preferred to reach the target electronic device; andselectively communicating, via the network interface, the messagethrough the fabric of devices toward the target electronic device usinga second network based at least in part on the Extended Unique LocalAddress.
 15. The method of claim 14, wherein identifying the ExtendedUnique Local Address of the IPv6 packet header comprises identifying afirst field identifying the fabric of devices, identifying a secondfield identifying that the second network is preferred to reach thetarget electronic device, and identifying a third field of the IPv6header of the message as comprising an extended unique identifier of thetarget electronic device, wherein the first field comprises 48 bits, thesecond field comprises 16 bits, and the third field comprises 64 bits.16. The method of claim 14, wherein selectively communicating themessage through the fabric of devices toward the target electronicdevice using the second network is based at least in part on whether thesecond network is available to the device.
 17. The method of claim 14,wherein selectively communicating the message through the fabric ofdevices toward the target electronic device using the second network isbased at least in part on whether the first device is an always-ondevice powered by an external power source.
 18. The method of claim 14,wherein selectively communicating the message through the fabric ofdevices toward the target electronic device using the second network isbased at least in part on whether the first device is an always-ondevice powered by an external power source.
 19. The method of claim 14,wherein selectively communicating the message through the fabric ofdevices toward the target electronic device using the second network isbased at least in part on one or more reliability factors relating to adesired reliability of the message.
 20. The method of claim 14, whereinselectively communicating the message through the fabric of devicestoward the target electronic device using the second network is based atleast in part on a type of the message that to be sent, a type ofnetwork over which the message is to be sent, a distance over which themessage may travel through the fabric to reach the target device, powersensitivity of devices used to communicate the message to the targetdevice, and a type of the target device as the one or more reliabilityfactors relating to a desired reliability of the message.